JP4415674B2 - Image forming state adjusting system, exposure method, exposure apparatus, program, and information recording medium - Google Patents

Description

  The present invention relates to an image formation state adjustment system, an exposure method and an exposure apparatus, a program, and an information recording medium. More specifically, the present invention relates to an image formation state adjustment that optimizes an image formation state of a pattern by a projection optical system used in the exposure apparatus. The present invention relates to a system, an exposure method and an exposure apparatus for realizing optimization of the imaging state, a program for causing a computer to optimize the imaging state of a pattern in the exposure apparatus, and an information recording medium on which the program is recorded.

Conventionally, a semiconductor element or a liquid crystal display device or the like when manufacturing in a photolithography process, a photomask or reticle (hereinafter generally referred to as "reticle") patterns, such as a photoresist, to the surface via the projection optical system A projection exposure apparatus that transfers onto a substrate such as a wafer or glass plate coated with a photosensitive agent, such as a step-and-repeat type reduction projection exposure apparatus (so-called stepper), or a step-and-scan type scanning projection exposure. An apparatus (so-called scanning stepper) or the like is used.

  By the way, when manufacturing semiconductor devices, etc., it is necessary to form different circuit patterns by stacking them on the substrate, so that they are already formed on the reticle on which the circuit pattern is formed and each shot region on the substrate. It is important to accurately overlay the formed pattern. In order to perform such superposition accurately, the imaging performance of the projection optical system is adjusted to a desired state (for example, to correct a magnification error of a transfer image of a reticle pattern with respect to a shot area (pattern) on a substrate). It is indispensable to be done. Even when the first layer reticle pattern is transferred to each shot area on the substrate, the imaging performance of the projection optical system is used to accurately transfer the second and subsequent reticle patterns to each shot area. It is desirable to adjust.

  As a premise for adjusting the imaging performance (a kind of optical characteristics) of the projection optical system, it is necessary to accurately measure (or detect) the imaging performance. As a method of measuring this imaging performance, a transfer image obtained by developing a substrate on which a projection image of a measurement pattern is transferred and exposed by using a measurement reticle on which a predetermined measurement pattern is formed, for example, A method for calculating imaging performance, specifically, Seidel's five aberrations (distortion, distortion, astigmatism, curvature of field, coma) based on the measurement result of the resist image The so-called “baking method” is mainly used. In addition, the measurement reticle formed by the projection optical system is measured by illuminating the measurement reticle with illumination light without actually performing exposure, and the above five aberrations are measured based on the measurement result. (Hereinafter referred to as “aerial image measurement method”) is also performed.

  However, according to the above-described printing method or aerial image measurement method, in order to obtain all the five aberrations, it is necessary to repeatedly perform individual measurement using a pattern suitable for each measurement. In addition, depending on the type and magnitude of the measured aberration, it is difficult to accurately adjust the projection optical system without considering the order. For example, when the coma aberration is large, the imaged pattern is not resolved, and accurate data cannot be obtained even if distortion, astigmatism, spherical aberration, and the like are measured in this state. Therefore, it is necessary to measure distortion and the like after adjusting the coma aberration to be below a certain level.

  In addition, with the recent high integration of semiconductor devices, etc., circuit patterns are becoming increasingly finer. Recently, it is not sufficient to correct Seidel's five aberrations (low-order aberrations). Therefore, it is required to adjust the overall imaging performance of the projection optical system including the above aberration. In order to adjust such comprehensive imaging performance, adjustment is performed by performing ray tracing calculation using data (curvature, refractive index, thickness, etc.) of individual lens elements constituting the projection optical system. It is necessary to calculate the power lens element and its adjustment amount.

  However, since the lens element data belongs to the confidential information of the exposure apparatus manufacturer, it is usually difficult for a service engineer or a user who repairs or adjusts the exposure apparatus to obtain it. In addition, since the above ray tracing calculation requires an enormous amount of time, it is unrealistic for an operator or the like to do this at the site.

  For the adjustment of the pattern imaging performance or imaging state of the projection optical system, for example, an imaging performance adjustment mechanism for adjusting the position and inclination of an optical element such as a lens element constituting the projection optical system is used. . However, the imaging performance depends on exposure conditions such as illumination conditions (such as illumination σ) and N. A. (Numerical aperture), and changes depending on the pattern used. Accordingly, the adjustment position of each optical element by the imaging performance adjustment mechanism that is optimum under a certain exposure condition is not necessarily the optimum adjustment position under other exposure conditions.

  Under such a background, arbitrary exposure conditions, for example, N.I. A. Therefore, it has been expected that a new system that can quickly calculate the adjustment position of each optical element by the imaging performance adjustment mechanism that draws the optimum imaging performance for the combination of the illumination σ and the target pattern has been expected.

  The present invention has been made under such circumstances, and a first object of the present invention is to rapidly optimize the formation state of a pattern projection image on an object under an arbitrary target exposure condition. An object of the present invention is to provide an image forming state optimization system.

  A second object of the present invention is to provide an exposure method and an exposure apparatus that optimizes the formation state of a pattern projection image on an object under an arbitrary target exposure condition and realizes accurate transfer of the pattern onto the object. It is to provide.

  A third object of the present invention is a program and information for causing a computer constituting a part of a control system of an exposure apparatus to execute processing for quickly optimizing the formation state of a pattern projection image on an object. It is to provide a recording medium.

According to a first aspect of the present invention, there is provided a method for optimizing the formation state of the projection image on an object used in an exposure apparatus that forms a projection image of a predetermined pattern on the object using a projection optical system. An image forming state adjusting system, comprising: an adjusting device that adjusts a forming state of the projection image on an object; and the projection under an exposure condition that is connected to the exposure device via a communication path and serves as at least one reference Information about the difference between the imaging performance of the optical system and a predetermined target value of the imaging performance, and the relationship between the imaging performance of the projection optical system under target exposure conditions and the coefficients of each term of the Zernike polynomial Using the sensitivity table, the wavefront aberration change table including a group of parameters indicating the relationship between the adjustment of the adjustment device and the change of the wavefront aberration of the projection optical system, and the relational expression of the adjustment amount of the adjustment device, the target Under exposure conditions A first image forming condition adjusting system comprising: a computer and for calculating the optimum adjustment amount of the adjusting device.

  In this specification, “exposure condition” means illumination condition (illumination σ (coherence factor), annular ratio or distribution of light quantity on the pupil plane of the illumination optical system, etc.), numerical aperture (NA) of the projection optical system. ), Target pattern type (extracted pattern or remaining pattern, dense pattern or isolated pattern, pitch and line width in case of line and space pattern, duty ratio, line width in case of isolated line pattern, vertical in case of contact hole It means conditions relating to exposure determined by a combination of width, width, distance between hole patterns (such as pitch), phase shift pattern, and whether or not there is a pupil filter in the projection optical system.

According to this, in the computer, information on the difference between the imaging performance of the projection optical system under at least one reference exposure condition and the predetermined target value of the imaging performance, and the projection optical system under the target exposure condition Zernike sensitivity table showing the relationship between the imaging performance of the Zernike polynomial and the coefficients of each term of the Zernike polynomial, adjustment of the adjustment device that adjusts the formation state of the projected image of the pattern on the object, and changes in the wavefront aberration of the projection optical system The optimum adjustment amount of the adjustment device under the target exposure condition is calculated using a relational expression between the wavefront aberration change table including the parameter group indicating the above relationship and the adjustment amount of the adjustment device. In other words, the adjustment amount for adjusting the optimum can easily be calculated, the optimum adjustment amount in the target exposure conditions issued its calculated becomes higher precision. Therefore, by adjusting the adjustment device based on the adjustment amount, it is possible to quickly optimize the formation state of the pattern projection image on the object under an arbitrary target exposure condition.

Optimum adjustment amount in the target exposure conditions are calculated based on the adjustment information and information about the imaging performance of the projection optical system of the definitive adjustment device under exposure conditions that a single reference even without least is as accurate Become . The predetermined target value of the imaging performance, the target value of the image-forming performance (for example, the aberration) also includes the case of zero.

  In this case, for example, the predetermined target value may be a target value of imaging performance at least one evaluation point of the projection optical system input from the outside. However, the predetermined target value can be zero when the target value is not given.

  In this case, the target value of the imaging performance can be a target value of the imaging performance at the selected representative point. Alternatively, the target value of the imaging performance is a target value of a coefficient set to improve the bad component based on the decomposition coefficient after the component decomposition of the imaging performance of the projection optical system by an aberration decomposition method. Can be the converted target value of the imaging performance.

  In the image forming state adjustment system of the present invention, the above-described relational expression for the computer to calculate the optimum adjustment amount is an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial. Can be.

  In this case, the computer can display the weight setting screen while displaying the image forming performance of the projection optical system under the exposure condition serving as the reference color-coded with an allowable value as a boundary. Alternatively, the weight can be set so that the weight of the portion exceeding the allowable value in the imaging performance of the projection optical system under the reference exposure condition is increased.

In the first image-forming conditioning system of the present invention, if the computer calculates the optimum adjustment amount using the above equation, the computer, the Zernike sensitivity table in the target exposure conditions, a plurality of reference It can be made by interpolation calculation based on the Zernike sensitivity table under the following exposure conditions. In such a case, for example, even if the Zernike sensitivity table under the target exposure condition is not prepared in advance, the target exposure is performed by interpolation calculation using, for example, interpolation using the Zernike sensitivity table under a plurality of reference exposure conditions. A Zernike sensitivity table under conditions can be obtained quickly.

In the first image forming state adjustment system of the present invention, the predetermined exposure condition may be the target exposure condition .

  In the first image formation state adjustment system of the present invention, it is preferable that the computer calculates the optimum adjustment amount in consideration of a constraint condition determined by a limit of the adjustment amount by the adjustment device. In such a case, adjustment of the adjusting device according to the calculated constraint condition is always possible.

In the first image formation state adjustment system of the present invention, the computer can be set from the outside as at least a part of the field of view of the projection optical system as an optimized field range. For example, in the case of a scanning exposure apparatus such as a so-called scanning stepper, it is not always necessary to optimize the imaging performance or the pattern transfer state on the object in the entire field of view of the projection optical system. Depending on the size of the mask (pattern area) to be used, it may not always be necessary to optimize the imaging performance or the pattern transfer state on the object in the entire field of view of the projection optical system. By setting the required range as the optimized field range from the outside, the calculation time for calculating the optimum adjustment amount can be shortened compared to the case where the entire field of view of the projection optical system is set as the optimized field range. Can do .

In the first image formation state adjustment system of the present invention, the adjustment of the adjustment device can be performed by a manual operation by an operator. However, the present invention is not limited to this, and the computer performs the adjustment based on the calculated adjustment amount. The adjustment device can be controlled.

According to a second aspect of the present invention, there is provided a method for optimizing the formation state of the projection image on the object used in an exposure apparatus that forms a projection image of a predetermined pattern on the object using a projection optical system. An image forming state adjusting system, comprising: an adjusting device that adjusts a forming state of the projected image on an object; and the adjustment under an exposure condition that is connected to the exposure device via a communication path and serves as at least one reference Information on the current wavefront aberration of the projection optical system obtained based on the adjustment information of the apparatus and the information on the wavefront aberration of the projection optical system, and under any exposure condition under the adjustment state of the adjustment apparatus according to the adjustment information based on the Zernike sensitivity table showing the relationship between the coefficients of the terms of imaging performance and Zernike polynomials of said projection optical system, calculate the imaging performance of the projection optical system in the exposure conditions before quinine meaning A second image forming condition adjusting system comprising: a computer and that.

According to this, the computer connected to the exposure apparatus via a communication path is obtained based on the adjustment information of the adjustment apparatus and the information on the wavefront aberration of the projection optical system under at least one reference exposure condition. Zernike showing the information of the wavefront aberration of the projection optical system, the relationship between the coefficients of the terms of imaging performance and Zernike polynomials of the projection optical system at any exposure conditions under adjustment state of the adjustment device according to the adjustment information Based on the sensitivity table , the imaging performance of the projection optical system under the arbitrary exposure conditions is calculated. Therefore, for example, by displaying the calculation result of the imaging performance on the display screen of the computer or the display unit on the exposure apparatus side connected thereto, anyone can easily view the display and easily project the projection optical system. It is possible to evaluate whether or not the imaging characteristics are satisfactory. In the second image formation state adjustment system, it is possible to easily determine the best exposure condition by calculating and displaying the imaging performance while setting various exposure conditions as the target exposure conditions.

  In this case, the arbitrary exposure condition may be a condition determined according to first information related to a pattern to be projected by the projection optical system and second information related to the pattern projection condition.

In this case, the second information can include the numerical aperture of the projection optical system and the illumination condition of the pattern .

  In the second image formation state adjustment system of the present invention, the computer creates a Zernike sensitivity table under the arbitrary exposure conditions by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. It can be.

In each of the first and second image forming state adjustment systems of the present invention, various communication paths can be used. For example, the communication path may be a local area network, and the communication path may include a public line. Alternatively, the communication path may include a wireless line.

  In each of the first and second image forming state adjustment systems of the present invention, the computer can be a control computer that controls each component of the exposure apparatus.

According to a third aspect of the present invention, there is provided an exposure method for transferring a predetermined pattern onto an object using a projection optical system, the imaging performance of the projection optical system under at least one reference exposure condition Information on the difference between the imaging performance and a predetermined target value of the imaging performance, a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system under target exposure conditions and coefficients of each term of the Zernike polynomial, and the projection A wavefront aberration change table including a parameter group indicating a relationship between adjustment of an adjustment device for adjusting a formation state of the projection image of the pattern on the object by the optical system and change of wavefront aberration of the projection optical system; and the adjustment device Calculating an optimum adjustment amount of the adjustment device under the target exposure condition using a relational expression with the adjustment amount; and adjusting device based on the calculated adjustment amount under the target exposure condition Adjust In state, process and transferred onto the object using the pattern the projection optical system; a first exposure method comprising.

According to this, information on the difference between the imaging performance of the projection optical system under at least one reference exposure condition and a predetermined target value of the imaging performance, and the projection optical system under the target exposure condition A Zernike sensitivity table showing the relationship between the imaging performance and the coefficients of each term of the Zernike polynomial, adjustment of the adjusting device for adjusting the formation state of the projection image of the pattern on the object by the projection optical system, and the projection optical system An optimum adjustment amount of the adjustment device under the target exposure condition is calculated using a relational expression between a wavefront aberration change table including a parameter group indicating a relationship with a change in the wavefront aberration and an adjustment amount of the adjustment device. That is, the optimal adjustment amount can be easily calculated, and the optimal adjustment amount under the calculated target exposure condition is highly accurate.

Therefore, by adjusting the adjustment device based on this adjustment amount, the formation state of the projected image of the pattern on the object can be quickly optimized under any target exposure condition, and the pattern can be accurately transferred onto the object. It becomes possible to do .

In the first exposure method of the present invention, the reference exposure condition may be the target exposure condition .

  In the first exposure method of the present invention, the above-mentioned relational expression used for calculating the optimum adjustment amount is an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial. Can be.

  According to a fourth aspect of the present invention, there is provided an exposure method for transferring a pattern onto an object via a projection optical system, the information relating to the wavefront aberration of the projection optical system, the imaging performance of the projection optical system, Based on the Zernike sensitivity table indicating the relationship with the coefficients of each term of the Zernike polynomial, the projection optical system is connected under a plurality of exposure conditions having different setting values with respect to the setting information of interest among the plurality of setting information in the transfer. In the second exposure method, image performance is calculated, and an exposure condition in which a setting value related to the setting information of interest is optimal is determined based on the imaging performance calculated for each exposure condition.

  According to this, based on the information on the wavefront aberration of the projection optical system, and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficient of each term of the Zernike polynomial, a plurality of transfer images in the transfer Of the setting information, the imaging performance of the projection optical system is calculated under a plurality of exposure conditions having different setting values with respect to the setting information of interest, and the setting information of interest is based on the imaging performance calculated for each of the exposure conditions. The exposure condition that optimizes the set value for is determined. Therefore, the best exposure conditions can be easily set for each setting information or for any number and type of setting information by using setting values that optimize the imaging performance, and can be set on the object via the projection optical system. It becomes possible to transfer the pattern with high accuracy.

  In this case, when the plurality of setting information includes information on a pattern to be projected by the projection optical system, an optimum setting value is determined using the information on the pattern as the setting information to be focused on. be able to.

  In the second exposure method of the present invention, when the plurality of setting information includes a plurality of information related to a projection condition of a pattern to be projected by the projection optical system, one of the plurality of information related to the projection condition is It is possible to determine an optimal setting value as the setting information of interest.

  In this case, the plurality of pieces of information regarding the projection condition may include optical information of the projection optical system and optical information of an illumination optical system that illuminates the pattern.

  In this case, the optical information of the illumination optical system may include a plurality of information related to the illumination conditions of the pattern.

  In the second exposure method of the present invention, the imaging performance can be calculated using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions.

  In this case, the Zernike sensitivity table corresponding to at least one of the plurality of exposure conditions may be created by interpolation calculation based on the Zernike sensitivity table corresponding to the other plurality of exposure conditions.

  In the second exposure method of the present invention, a wavefront aberration change table showing a relationship between an adjustment by a device for adjusting a pattern image formation state by the projection optical system on the object and a change in wavefront aberration of the projection optical system; Based on the Zernike sensitivity table, it is possible to determine an optimum adjustment amount of the adjustment device under an exposure condition in which a setting value related to the noticed setting information is optimum.

  In this case, when the pattern is transferred onto the object under an exposure condition in which a setting value related to the setting information of interest is optimum, at least one optical element of the projection optical system corresponds to the optimum adjustment amount. Can be adjusted. Alternatively, the optimum adjustment amount can be calculated using a weighting function that weights at least one term of the Zernike polynomial. Alternatively, the imaging performance can be calculated using a Zernike sensitivity table that differs at least in a part of the plurality of exposure conditions. In this case, the Zernike sensitivity table corresponding to at least one of the plurality of exposure conditions may be created by interpolation calculation based on the Zernike sensitivity table corresponding to the other plurality of exposure conditions.

  According to a fifth aspect of the present invention, there is provided an exposure method for transferring a pattern onto an object via a projection optical system, the information relating to the wavefront aberration of the projection optical system, the imaging performance of the projection optical system, A Zernike sensitivity table showing the relationship between the coefficients of each term of the Zernike polynomial, and a relationship between the adjustment of the pattern image formation state by the projection optical system on the object and the change in wavefront aberration of the projection optical system 3 is a third exposure method for determining an optimum adjustment amount of the adjustment device under an exposure condition in which the imaging performance of the projection optical system is optimum.

  According to this, the information on the wavefront aberration of the projection optical system, the Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, and the projection optics on the object An exposure condition under which the imaging performance of the projection optical system is optimized based on the adjustment of the pattern image formation state by the system and the wavefront aberration change table showing the relationship between the change of the wavefront aberration of the projection optical system The optimum adjustment amount of the adjustment device below is determined. For this reason, it is possible to determine the optimum adjustment amount of the adjusting device under the exposure conditions under which the imaging performance of the projection optical system is optimal based on the information on the wavefront aberration of the known projection optical system and the information on the pattern. It is possible to transfer the pattern onto the object with high accuracy via the projection optical system by adjusting the adjusting device using the determined adjustment amount and performing exposure.

  In this case, when the pattern is transferred onto the object under an exposure condition that optimizes the imaging performance, at least one optical element of the projection optical system is adjusted according to the optimal adjustment amount. It can be. Alternatively, the optimum adjustment amount can be calculated using a weighting function that weights at least one term of the Zernike polynomial.

  In the third exposure method of the present invention, the adjustment device that is optimal for the imaging performance of the projection optical system respectively under a plurality of exposure conditions having different setting values with respect to at least one of the plurality of setting information in the transfer. The adjustment amount can be determined.

  In this case, the optimum adjustment amount can be determined using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions.

  In this case, the Zernike sensitivity table corresponding to at least one of the plurality of exposure conditions may be created by interpolation calculation based on the Zernike sensitivity table corresponding to the other plurality of exposure conditions. Alternatively, when the plurality of setting information includes information related to a pattern to be projected by the projection optical system, the adjustment device that optimizes the imaging performance of the projection optical system under a plurality of exposure conditions with different patterns. The optimum adjustment amount can be determined.

  Alternatively, the plurality of setting information includes projection information related to a projection condition of a pattern to be projected by the projection optical system, and imaging performance of the projection optical system under a plurality of exposure conditions having different setting values related to the projection information, respectively. It is possible to determine an optimal adjustment amount of the adjustment device that is optimal.

  In this case, the information regarding the projection condition includes optical information of the projection optical system and optical information of an illumination optical system that illuminates the pattern, and a plurality of setting values regarding at least one of the two optical information are different. It is possible to determine an optimum adjustment amount of the adjusting device that optimizes the imaging performance of the projection optical system under the exposure conditions.

  In this case, the optical information of the illumination optical system includes a plurality of pieces of illumination information related to the illumination conditions of the pattern, and the projection optical system respectively under a plurality of exposure conditions having different setting values related to at least one of the plurality of pieces of illumination information. It is possible to determine an optimal adjustment amount of the adjusting device that optimizes the imaging performance.

  According to a sixth aspect of the present invention, there is provided an exposure apparatus for transferring a pattern onto an object via a projection optical system, wherein at least a plurality of setting information relating to a projection condition of a pattern to be projected by the projection optical system. A single setting device for setting an exposure condition whose set value is variable; Zernike indicating information on wavefront aberration of the projection optical system, and the relationship between the imaging performance of the projection optical system and coefficients of each term of the Zernike polynomial Based on the sensitivity table, the imaging performance of the projection optical system is calculated under a plurality of exposure conditions with different setting values with respect to the setting information of interest among the plurality of setting information, and the result calculated for each exposure condition is calculated. A first exposure apparatus comprising: an arithmetic device that determines an exposure condition that optimizes a setting value related to the setting information of interest based on image performance.

  According to this, an exposure condition whose setting value is variable is set by at least one of a plurality of setting information related to the projection condition of the pattern to be projected by the projection optical system by the setting device. Then, the arithmetic device, based on the information on the wavefront aberration of the projection optical system, and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, Of these, the imaging performance of the projection optical system is calculated under a plurality of exposure conditions with different setting values with respect to the setting information of interest, and the setting values of the setting information of interest based on the imaging performance calculated for each exposure condition Determines the optimum exposure conditions. Therefore, the best exposure conditions can be easily set for each setting information or for any number and type of setting information by using setting values that optimize the imaging performance, and can be set on the object via the projection optical system. It becomes possible to transfer the pattern with high accuracy.

  In this case, the imaging performance can be calculated using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions.

  In this case, the Zernike sensitivity table corresponding to at least one of the plurality of exposure conditions may be created by interpolation calculation based on the Zernike sensitivity table corresponding to the other plurality of exposure conditions.

  The first exposure apparatus of the present invention further includes an adjustment device that adjusts the formation state of the pattern image by the projection optical system on the object, and the adjustment by the adjustment device and the change of the wavefront aberration of the projection optical system In accordance with the wavefront aberration change table showing the relationship of the above and the Zernike sensitivity table, the optimum adjustment amount of the adjustment device under the exposure conditions in which the setting value related to the setting information of interest is optimum is determined. Can do.

  In this case, when the pattern is transferred onto the object under an exposure condition in which a setting value related to the setting information of interest is optimum, at least one optical element of the projection optical system corresponds to the optimum adjustment amount. Can be adjusted. Alternatively, the optimum adjustment amount can be calculated using a weighting function that weights at least one term of the Zernike polynomial.

  According to a seventh aspect of the present invention, there is provided an exposure apparatus for transferring a pattern onto an object via a projection optical system, wherein the adjustment apparatus adjusts a pattern image forming state by the projection optical system on the object. Information on the wavefront aberration of the projection optical system, a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, adjustment by the adjusting device, and the projection optical system An arithmetic unit that determines an optimal adjustment amount of the adjustment device under exposure conditions under which the imaging performance of the projection optical system is optimal based on a wavefront aberration change table showing a relationship with a change in wavefront aberration; A second exposure apparatus.

  According to this, the arithmetic device includes information on the wavefront aberration of the projection optical system, a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, and projection optics on the object. Exposure that optimizes the imaging performance of the projection optical system based on a wavefront aberration change table showing the relationship between the adjustment by the adjusting device that adjusts the formation state of the pattern image by the system and the change of the wavefront aberration of the projection optical system The optimum adjustment amount of the adjustment device under the conditions is determined. For this reason, the optimum adjustment amount of the adjusting device under the exposure conditions that optimizes the imaging performance of the projection optical system is determined by the arithmetic unit only by giving information on the wavefront aberration of the projection optical system and information on the pattern. Then, by performing exposure with the adjustment device adjusted using the determined adjustment amount, the pattern can be accurately transferred onto the object via the projection optical system.

  In this case, the optimum adjustment amount can be calculated using a weighting function that weights at least one term of the Zernike polynomial.

  In the second exposure apparatus of the present invention, the adjustment apparatus is configured to optimize the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to at least one of the plurality of setting information in the transfer. The adjustment amount can be determined.

  In this case, the optimum adjustment amount can be determined using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions.

  In this case, the Zernike sensitivity table corresponding to at least one of the plurality of exposure conditions may be created by interpolation calculation based on the Zernike sensitivity table corresponding to the other plurality of exposure conditions.

  According to an eighth aspect of the present invention, there is provided an exposure apparatus for transferring a pattern onto an object via a projection optical system, wherein at least a plurality of setting information relating to a projection condition of a pattern to be projected by the projection optical system. A single setting device for setting an exposure condition whose set value is variable; Zernike indicating information on wavefront aberration of the projection optical system, and the relationship between the imaging performance of the projection optical system and coefficients of each term of the Zernike polynomial Based on the sensitivity table, in order to calculate the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to the setting information of interest among the plurality of setting information, at least one of the plurality of exposure conditions A partly different Zernike sensitivity table is used, and at least one of the different Zernike sensitivity tables is interpolated based on a plurality of other Zernike sensitivity tables. A third exposure apparatus comprising; computing device and to create.

  According to this, an exposure condition whose setting value is variable is set by at least one of a plurality of setting information related to the projection condition of the pattern to be projected by the projection optical system by the setting device. Then, the arithmetic device, based on the information on the wavefront aberration of the projection optical system, and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, In order to calculate the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to the setting information to be noticed, a different Zernike sensitivity table is used in at least a part of the plurality of exposure conditions, and the different Zernike At least one of the sensitivity tables is created by interpolation calculation based on a plurality of other Zernike sensitivity tables. Therefore, even if the Zernike sensitivity table for each of the plurality of exposure conditions is not prepared in advance, the Zernike sensitivity table under the target exposure condition by the interpolation calculation based on the Zernike sensitivity table under the other plurality of exposure conditions. Can be obtained.

  According to a ninth aspect of the present invention, there is provided an exposure method for transferring a pattern onto an object via a projection optical system, the information relating to the wavefront aberration of the projection optical system, the imaging performance of the projection optical system, Based on a Zernike sensitivity table indicating the relationship with the coefficients of each term of the Zernike polynomial, a plurality of setting values with different setting values with respect to the setting information of interest among a plurality of setting information regarding the projection conditions of the pattern to be projected by the projection optical system In order to calculate the imaging performance of the projection optical system under each of the exposure conditions, a different Zernike sensitivity table is used in at least a part of the plurality of exposure conditions, and at least one of the different Zernike sensitivity tables is used as another A fourth exposure method is created by interpolation calculation based on a plurality of Zernike sensitivity tables.

  According to this, even when the Zernike sensitivity table for each of the plurality of exposure conditions is not prepared in advance, the interpolation calculation based on the Zernike sensitivity table for the other plurality of exposure conditions is performed under the target exposure condition. A Zernike sensitivity table can be obtained.

According to a tenth aspect of the present invention, there is provided an exposure apparatus that illuminates a mask with an energy beam and transfers a pattern formed on the mask onto an object via a projection optical system. an adjusting device for adjusting a formation state on the object; are connected via a signal line to the adjusting device, imaging performance and said imaging performance of prior Kito projection optical system in the exposure conditions comprising at least one reference Information on the difference from the predetermined target value , a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system under target exposure conditions and the coefficients of each term of the Zernike polynomial, adjustment of the adjusting device, and by using the wavefront aberration change table consisting of a group of parameters indicating the relationship between the change in the wavefront aberration of the projection optical system, the relationship between the adjustment amount of the adjusting device, optimum adjustment of the adjusting device in the target exposure conditions A fourth exposure apparatus provided with; is calculated, based on the adjustment amount that is calculated, processing unit and for controlling the adjustment device.

According to this, in the processing apparatus, the connection of the projection optical system under the target exposure condition based on the adjustment information of the adjustment apparatus and the information regarding the imaging performance of the projection optical system under at least one reference exposure condition. A Zernike sensitivity table indicating the relationship between the image performance and the difference between the imaging performance and a predetermined target value, the imaging performance of the projection optical system under the target exposure conditions, and the coefficients of each term of the Zernike polynomial, and a pattern Between the adjustment of the adjusting device that adjusts the formation state of the projected image on the object and the change in the wavefront aberration of the projection optical system, and the relationship between the adjustment amount of the adjusting device Is used to calculate the optimum adjustment amount of the adjustment device under the target exposure condition , and the adjustment device is controlled based on the calculated adjustment amount. That is, the optimum adjustment amount can easily be found, since the adjustment device is adjusted based on the adjustment amount that is calculated, is formed state on the object of the projected image of the pattern in any target exposure conditions Optimized almost fully automatically.

In this case, the predetermined exposure condition may be at least one reference exposure condition. In such a case, at least one reference exposure condition in which an adjustment amount for optimally adjusting the imaging performance of the projection optical system is obtained in advance as the predetermined exposure condition can be determined. The optimum adjustment amount under the target exposure condition calculated based on the adjustment information of the adjustment device under the exposure condition and the information regarding the imaging performance of the projection optical system is high in accuracy .

In the fourth exposure apparatus of the present invention, the reference exposure condition may be the target exposure condition.

The fourth exposure apparatus of the present invention may further comprise a wavefront measuring instrument for measuring the wavefront aberration of the projection optical system.

In this case, the apparatus may further comprise: an object stage that holds the object; and a conveyance system that carries the wavefront measuring instrument onto the object stage and carries it out of the object stage .

  In the fourth exposure apparatus of the present invention, when the processing apparatus calculates the optimum adjustment amount using the above-described relational expression, the predetermined target value is input from the outside, and at least one of the projection optical systems It can be the target value of the imaging performance at the evaluation point.

  The target value of the imaging performance can be a target value of the imaging performance at the selected representative point, or the target value of the imaging performance is the imaging performance of the projection optical system. Is decomposed into components by the aberration decomposition method, and the target value of the coefficient set to improve the bad component based on the decomposed coefficient after the decomposition is the converted target value of the imaging performance.

  In the fourth exposure apparatus of the present invention, when the processing apparatus calculates the optimum adjustment amount using the above-described relational expression, the relational expression weights an arbitrary term in each term of the Zernike polynomial. It can be assumed that the equation includes a weighting function.

  In this case, the processing apparatus may display the weighting setting screen while displaying the imaging performance of the projection optical system under the predetermined exposure condition in a color-coded manner with an allowable value as a boundary.

  In the fourth exposure apparatus of the present invention, when the processing apparatus calculates the optimum adjustment amount using the above-described relational expression, the processing apparatus uses the Zernike sensitivity table under the target exposure conditions as a plurality of reference exposures. It can be made by interpolation calculation based on the Zernike sensitivity table under conditions.

According to an eleventh aspect of the present invention, there is provided an exposure apparatus that illuminates a mask with an energy beam and transfers a pattern formed on the mask onto an object via a projection optical system. An adjustment device that adjusts the formation state of the adjustment device; the adjustment information of the adjustment device and the information on the wavefront aberration of the projection optical system that are connected to the adjustment device via a communication path and that are at least one reference exposure condition Information on the current wavefront aberration of the projection optical system obtained based on the above , the imaging performance of the projection optical system under the arbitrary exposure conditions under the adjustment state of the adjustment device according to the adjustment information , and each term of the Zernike polynomial of it based on the Zernike sensitivity table showing the relationship between the coefficient before and processor for calculating the imaging performance of the projection optical system in the exposure conditions of quinine meaning; the fifth with the It is an optical device.

According to this, in the processing device connected to the adjustment device via the communication path, it is obtained based on the adjustment information of the adjustment device and the information on the wavefront aberration of the projection optical system under at least one reference exposure condition. shows the information of the wavefront aberration of the current of the projection optical system, the relationship between the coefficients of the terms of imaging performance and Zernike polynomials of the projection optical system at any exposure conditions under adjustment state of the adjustment device according to the adjustment information Based on the Zernike sensitivity table , the imaging performance of the projection optical system under the arbitrary exposure conditions is calculated. Therefore, for example, by displaying the calculation result of the imaging performance on a display screen or the like, anyone can easily evaluate whether the imaging characteristics of the projection optical system should be satisfied simply by looking at the display. Is possible. In the fifth exposure apparatus, it is possible to easily determine the best exposure condition by calculating and displaying the imaging performance by setting various exposure conditions as the target exposure conditions.

  In this case, the arbitrary exposure condition may be a condition determined according to first information related to a pattern to be projected by the projection optical system and second information related to the pattern projection condition.

In this case, the second information can include the numerical aperture of the projection optical system and the illumination condition of the pattern .

In the fifth exposure apparatus of the present invention, the processing apparatus creates a Zernike sensitivity table under the arbitrary exposure conditions by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. be able to.

From a twelfth aspect, the present invention includes an adjustment device that forms a projection image of a predetermined pattern on an object using a projection optical system and adjusts the formation state of the projection image on the object. A program for causing a computer constituting a part of a control system of an exposure apparatus to execute a predetermined process , information on an adjustment amount of the adjustment apparatus under at least one reference exposure condition, and the reference exposure condition In response to an input of a difference between the imaging performance of the projection optical system and a predetermined target value of the imaging performance in the imaging optical performance of the projection optical system under a target exposure condition and a Zernike polynomial A Zernike sensitivity table showing the relationship between the coefficient of each term, a wavefront aberration change table consisting of parameters indicating the relationship between the adjustment of the adjusting device and the change of the wavefront aberration of the projection optical system, and the adjustment amount. The procedure for calculating the optimum adjustment amount of the adjusting device in the target exposure conditions using the engagement type, a first program for causing the computer to execute.

The computer in which this program is installed has information on the adjustment amount of the adjusting device under at least one reference exposure condition and the imaging performance of the projection optical system and the imaging performance under the reference exposure condition. In response to the input of the difference information from the predetermined target value , the computer responds to the difference, the imaging performance of the projection optical system under the target exposure condition, and the coefficients of each term of the Zernike polynomial. Zernike sensitivity table showing the relationship of the above, a wavefront aberration change table consisting of a parameter group showing the relationship between the adjustment of the adjusting device and the change of the wavefront aberration of the projection optical system, and a relational expression between the adjustment amount and the target An optimum adjustment amount of the adjustment device under the exposure condition is calculated. That is , the optimal adjustment amount can be easily calculated, and the optimal adjustment amount under the calculated target exposure condition is highly accurate. Therefore, by adjusting the adjustment device based on this adjustment amount, it becomes possible to quickly optimize the image formation state of the pattern by the projection optical system under an arbitrary target exposure condition. As described above, the first program of the present invention causes the computer to calculate the optimum adjustment amount under the target exposure condition, specifically, processing for quickly optimizing the pattern imaging state by the projection optical system. Can be executed .

  In this case, it is possible to cause the computer to further execute a procedure for displaying the target value setting screen at each evaluation point in the field of view of the projection optical system. In such a case, the predetermined target value can be the target value of the imaging performance at at least one representative point of the projection optical system set in response to the display of the setting screen.

In the first program of the present invention, prior to Symbol and component degraded by aberrations decomposition method the imaging performance of the projection optical system, procedures and for displaying the setting screen of the target value along with the decomposition coefficients after decomposition; the setting screen And a step of converting the target value of the coefficient set in response to the display into the target value of the imaging performance. In this case, the relational expression may be an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial.

  In this case, the image forming performance of the projection optical system under the reference exposure condition is color-coded with an allowable value as a boundary, and the procedure for displaying the weight setting screen is further executed by the computer. can do.

In the first program of the present invention, the Zernike sensitivity table before Symbol target exposure conditions, the procedure for creating the interpolation calculation based on the Zernike sensitivity table in the exposure conditions comprising a plurality of reference, further the computer to execute Can be.

In the first program of the present invention, prior SL taking into account the constraints defined by the limits of the adjustment amount by the adjustment device, the procedure for correcting the optimum adjustment amount the calculated, and that further the computer to execute be able to.

In the first program of the present invention, the reference exposure condition may be the target exposure condition .

  In the first program of the present invention, it is possible to cause the computer to further execute a procedure for controlling the adjustment device based on the calculated adjustment amount.

From a thirteenth aspect, the present invention includes an adjustment device that forms a projection image of a predetermined pattern on an object using a projection optical system and adjusts the formation state of the projection image on the object. a program for executing a predetermined process on a computer that forms part of a control system of the exposure apparatus, adjustment information and information of the wavefront aberration of the projection optical system of the adjusting device in the exposure conditions comprising at least one reference Information on the current wavefront aberration of the projection optical system obtained based on the above, and the imaging performance and Zernike polynomial terms of the projection optical system under any exposure conditions under the adjustment state of the adjustment device according to the adjustment information out the calculation result; based on the Zernike sensitivity table showing the relationship between the coefficient of the procedure and of calculating the imaging performance of the projection optical system in the arbitrary exposure conditions Procedure for the; which is a second program for causing the computer to execute.

The computer that the program is installed, the information of the adjustment information and wavefront aberration of the projection optical system of the adjusting device in the exposure conditions comprising at least one reference is input, in response thereto, a computer, these Information on the current wavefront aberration of the projection optical system obtained on the basis of the information of the imaging optical performance of the projection optical system under an arbitrary exposure condition under the adjustment state of the adjustment device according to the adjustment information and the Zernike polynomial Based on the Zernike sensitivity table indicating the relationship with the coefficient of each term, the imaging performance of the projection optical system under the arbitrary exposure conditions is calculated, and the calculation result is output . Therefore, for example, it is possible for anyone to easily evaluate whether or not the imaging characteristics of the projection optical system should be satisfied based on the output calculation results of the imaging performance. In the second program, the best exposure condition can be easily determined by inputting various exposure conditions as the target exposure condition and outputting the calculation result of the imaging performance.

  In this case, the arbitrary exposure condition may be a condition determined according to first information related to a pattern to be projected by the projection optical system and second information related to the pattern projection condition.

In this case, the second information can include the numerical aperture of the projection optical system and the illumination condition of the pattern .

  In the second program of the present invention, the computer is further caused to execute a procedure for creating a Zernike sensitivity table under the arbitrary exposure conditions by interpolation calculation based on the Zernike sensitivity tables under a plurality of reference exposure conditions. Can be.

  According to a fourteenth aspect of the present invention, there is provided a computer program for causing an exposure apparatus that transfers a pattern onto an object via a projection optical system to execute a predetermined process, the information relating to the wavefront aberration of the projection optical system; In response to the input of the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, a setting value is set for the setting information to be noticed among the plurality of setting information in the transfer. The imaging performance of the projection optical system is calculated for each of a plurality of different exposure conditions, and the exposure condition that optimizes the setting value for the focused setting information is determined based on the imaging performance calculated for each exposure condition. It is a 3rd program which makes a computer perform a procedure.

  When information about the wavefront aberration of the projection optical system and the Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial are input to the computer where this program is installed, In response, the computer calculates the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values for the setting information of interest among a plurality of setting information in transfer, and is calculated for each exposure condition. Based on the imaging performance to be determined, an exposure condition that optimizes the setting value related to the focused setting information is determined. Thereby, it is possible to execute processing for quickly optimizing the formation state of the pattern projection image on the object.

  According to a fifteenth aspect of the present invention, there is provided an exposure apparatus including an adjustment device that adjusts a formation state of a projection image of the pattern on the object in order to transfer the pattern onto the object via the projection optical system. A computer program for executing a predetermined process, a Zernike sensitivity table showing information on the wavefront aberration of the projection optical system, the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, In response to an input of a wavefront aberration change table indicating a relationship between the adjustment by the adjustment device and a change in the wavefront aberration of the projection optical system, the adjustment under an exposure condition in which the imaging performance of the projection optical system is optimized A fourth program for causing the computer to execute a procedure for determining an optimum adjustment amount of the apparatus.

  In the computer in which this program is installed, information on the wavefront aberration of the projection optical system, a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, and adjustment by the adjustment device In response to the input of the wavefront aberration change table indicating the relationship with the change in the wavefront aberration of the projection optical system, the computer responds by receiving the above-mentioned exposure conditions under which the imaging performance of the projection optical system is optimal. The optimum adjustment amount of the adjustment device is determined. Therefore, by adjusting the adjustment device based on the determined adjustment amount, it is possible to execute processing for quickly optimizing the formation state of the pattern projection image on the object.

  According to a sixteenth aspect of the present invention, there is provided a computer program for causing an exposure apparatus that transfers a pattern onto an object via a projection optical system to execute a predetermined process, the information relating to the wavefront aberration of the projection optical system, and A plurality of settings relating to the projection conditions of the pattern to be projected by the projection optical system in response to the input of the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial In order to calculate the imaging performance of the projection optical system in each of a plurality of exposure conditions having different setting values with respect to the setting information to which attention is paid among the information, a Zernike sensitivity table that is different in at least a part of the plurality of exposure conditions is used. A step of creating at least one of the different Zernike sensitivity tables by interpolation calculation based on a plurality of other Zernike sensitivity tables; A fifth program to be executed by the computer.

  When information about the wavefront aberration of the projection optical system and a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial are input to a computer in which this program is installed In response to this, in the computer, each of the projection optical systems under a plurality of exposure conditions having different setting values with respect to setting information of interest among a plurality of setting information related to the projection conditions of the pattern to be projected by the projection optical system. In order to calculate the imaging performance, different Zernike sensitivity tables are used in at least a part of the plurality of exposure conditions, and at least one of the different Zernike sensitivity tables is interpolated based on the other Zernike sensitivity tables. Create by. As a result, even if the Zernike sensitivity table for each of the plurality of exposure conditions is not prepared in advance, the Zernike sensitivity under the target exposure condition can be obtained by interpolation calculation based on the Zernike sensitivity table for the other plurality of exposure conditions. A table can be obtained. Further, since the imaging performance of the projection optical system is calculated under the plurality of exposure conditions using the obtained Zernike sensitivity table, it is possible to set optimal exposure conditions based on the calculation result.

  The first to fifth programs of the present invention can be targeted for sale in a state of being recorded on an information recording medium. Therefore, from the seventeenth viewpoint, the present invention can be said to be an information recording medium readable by a computer on which any one of the first to fifth programs of the present invention is recorded.

The present invention, from the viewpoint of the 18th step and obtaining information about a plurality of optical elements each surface shape; with assembling the projection optical system by assembling the plurality of optical elements in the lens barrel in a predetermined positional relationship, Obtaining information relating to the spacing of the optical surfaces of each optical element being assembled; measuring the wavefront aberration of the projection optical system after assembling; information relating to the surface shape of each optical element; Correcting the known basic optical data based on the information about the distance between the optical surfaces, and reproducing the optical data in the actual production process of the projection optical system; and a predetermined degree of freedom of each optical element; The relationship between the unit driving amount for each direction and the change amount of the coefficient of each term of the Zernike polynomial is a basic adjustment database including a wavefront aberration change table calculated based on the design value of the projection optical system. Using the corrected database and the measurement result of the measured wavefront aberration, information on the adjustment amount of each lens element in each direction of freedom is obtained. Calculating and adjusting the projection optical system so that the measured wavefront aberration is optimized by driving the at least one optical element in the direction of at least one degree of freedom based on the calculation result ; ; Ru manufacturing method der of the projection optical system including.

  According to a nineteenth aspect of the present invention, there is provided an exposure apparatus manufacturing method for transferring a predetermined pattern onto an object via a projection optical system, the manufacturing method of the projection optical system; A step of incorporating the projection optical system into the exposure apparatus body; a step of measuring the wavefront aberration of the projection optical system incorporated in the exposure apparatus body; and a unit driving amount of each optical element in a predetermined degree of freedom direction. The optical element using a database including a wavefront aberration change table calculated based on the design value of the projection optical system and the measured wavefront aberration, the relationship between the change amount of the coefficient of each term of the Zernike polynomial and the design value of the projection optical system And calculating the adjustment amount information in each of the degrees of freedom directions, and driving the at least one optical element in the directions of at least one degree of freedom based on the calculation result. That.

  According to a twentieth aspect of the present invention, there is provided an imaging performance measurement method for a projection optical system that projects a pattern onto an object, the information relating to the wavefront aberration of the projection optical system, and the imaging performance of the projection optical system. And the Zernike sensitivity table indicating the relationship between the coefficients of each term of the Zernike polynomial and the projection optical system connected under a plurality of conditions with different setting values with respect to the setting information of interest among the plurality of setting information in the projection. In order to calculate image performance, a different Zernike sensitivity table is used under at least a part of the plurality of conditions, and at least one of the different Zernike sensitivity tables is created by interpolation calculation based on the other Zernike sensitivity tables. This is a method for measuring the imaging performance of the projection optical system.

  In this case, the plurality of setting information may include information related to a projection condition of a pattern to be projected by the projection optical system.

  In this case, the information regarding the projection condition can include optical information of the projection optical system and optical information of an illumination optical system that illuminates the pattern.

  In the imaging performance measuring method of the present invention, the plurality of setting information may include information related to a pattern to be projected by the projection optical system.

  In addition, in the lithography process, by performing exposure using any one of the first to fourth exposure methods of the present invention, a pattern can be formed on the object with high accuracy, thereby achieving higher integration. Microdevices can be manufactured with high yield. Therefore, from another viewpoint, the present invention can be said to be a device manufacturing method using any one of the first to fourth exposure methods of the present invention.

It is a figure which shows the structure of the computer system which concerns on one Embodiment of this invention. It is a figure which shows schematically the structure of the 1st exposure apparatus 922 ₁ of FIG. It is sectional drawing which shows an example of a wavefront aberration measuring device. 4A is a diagram showing a light beam emitted from the microlens array when there is no aberration in the optical system, and FIG. 4B is a diagram showing a light beam emitted from the microlens array when there is aberration in the optical system. is there. It is a flowchart which shows the process algorithm performed by CPU in a 2nd communication server. It is a flowchart (the 1) which shows the process in step 118 of FIG. It is a flowchart (the 2) which shows the process in step 118 of FIG. 6 is a flowchart (No. 3) showing a process in step 118 of FIG. 6 is a flowchart (No. 4) showing a process in step 118 of FIG. 6 is a flowchart (No. 5) showing a process in step 118 of FIG. It is a conceptual diagram which shows the interpolation method for producing a ZS file. It is a figure which shows typically the process at the time of a constraint condition violation. It is a figure which shows arrangement | positioning of the drive shaft of the movable lens 13 _i . It is a flowchart (the 1) which shows the process in step 116 of FIG. It is a flowchart (the 2) which shows the process in step 116 of FIG. It is a flowchart (the 3) which shows the process in step 116 of FIG. 6 is a flowchart (No. 4) showing a process in step 116 of FIG. It is a flowchart (the 5) which shows the process in step 116 of FIG. It is a flowchart (the 1) which shows the process in step 120 of FIG. It is a flowchart (the 2) which shows the process in step 120 of FIG. It is a flowchart which shows the manufacturing process of a projection optical system roughly. It is a figure which shows the structure of the computer system which concerns on a modification.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows the overall configuration of a computer system as an image forming state adjustment system according to an embodiment of the present invention.

  A computer system 10 shown in FIG. 1 is an in-house LAN system constructed in a semiconductor factory of a device manufacturer (hereinafter referred to as “manufacturer A” as appropriate) that is a user of a device manufacturing apparatus such as an exposure apparatus. The computer system 10 includes a lithography system 912 installed in a clean room including a first communication server 920, and a first communication server 920 constituting the lithography system 912 via a local area network (LAN) 926 as a communication path. And a second communication server 930 connected to each other.

The lithography system 912 includes a first communication server 920, a first exposure apparatus 922 ₁ , a second exposure apparatus 922 ₂ , and a third exposure apparatus 922 ₃ (hereinafter referred to as “exposure” as appropriate). Device 922 ").

FIG. 2 shows a schematic configuration of the first exposure apparatus 922 ₁ . The exposure apparatus 922 ₁ is a step-and-repeat reduction projection exposure apparatus using a pulse laser light source as an exposure light source (hereinafter referred to as “light source”), that is, a so-called stepper.

The exposure apparatus 922 ₁ is a reticle stage as a mask stage for holding an illumination system including a light source 16 and an illumination optical system 12, and a reticle R as a mask illuminated by exposure illumination light EL as an energy beam from the illumination system. RST, projection optical system PL for projecting exposure illumination light EL emitted from reticle R onto wafer W (image plane) as an object, and Z tilt stage 58 as an object stage for holding wafer W are mounted. Wafer stage WST and control system thereof are provided.

As the light source 16, a pulsed ultraviolet light source that outputs pulsed light in the vacuum ultraviolet region such as an F ₂ laser (output wavelength 157 nm) or an ArF excimer laser (output wavelength 193 nm) is used here. The light source 16 may be a light source that outputs pulsed light in the far ultraviolet region or ultraviolet region, such as a KrF excimer laser (output wavelength 248 nm).

  The light source 16 is actually a clean room in which a chamber 11 in which an exposure apparatus main body including the constituent elements of the illumination optical system 12 and the reticle stage RST, the projection optical system PL, the wafer stage WST, and the like is housed is installed. It is installed in another low clean room, and is connected to the chamber 11 via a light transmission optical system (not shown) including at least a part of an optical axis adjusting optical system called a beam matching unit. In this light source 16, based on the control information TS from the main controller 50, an internal controller turns on / off the output of the laser beam LB, energy per pulse of the laser beam LB, oscillation frequency (repetition frequency), The center wavelength, the spectrum half width (wavelength width), and the like are controlled.

  The illumination optical system 12 includes a beam shaping / illuminance uniformizing optical system 20 including a cylinder lens, a beam expander (all not shown), an optical integrator (homogenizer) 22, and the like, an illumination system aperture stop plate 24, a first relay lens. 28A, a second relay lens 28B, a reticle blind 30, a mirror M for bending an optical path, a condenser lens 32, and the like. As the optical integrator, a fly-eye lens, a rod integrator (an internal reflection type integrator), a diffractive optical element, or the like can be used. In the present embodiment, since a fly-eye lens is used as the optical integrator 22, it is also referred to as a fly-eye lens 22 below.

  The beam shaping / illuminance uniformity optical system 20 is connected to a light transmission optical system (not shown) through a light transmission window 17 provided in the chamber 11. The beam shaping / illuminance equalizing optical system 20 shapes the cross-sectional shape of the laser beam LB that is pulsed by the light source 16 and incident through the light transmission window 17 using, for example, a cylinder lens or a beam expander. The fly-eye lens 22 located on the exit end side in the beam shaping / illumination uniformity optical system 20 is irradiated with a laser beam whose cross-sectional shape is shaped in order to illuminate the reticle R with a uniform illumination distribution. A surface light source (secondary light source) composed of a large number of point light sources (light source images) is formed on the exit-side focal plane arranged so as to substantially coincide with the pupil plane of the illumination optical system 12. Hereinafter, the laser beam emitted from the secondary light source is referred to as “illumination light EL”.

  An illumination system aperture stop plate 24 made of a disk-like member is disposed in the vicinity of the exit-side focal plane of the fly-eye lens 22. The illumination system aperture stop plate 24 is provided with an aperture stop (small aperture) made up of, for example, a normal circular aperture, and an aperture stop (small size) for reducing the σ value that is a coherence factor made up of a small circular aperture at substantially equal angular intervals. σ stop), an annular aperture stop for annular illumination (annular stop), and a modified aperture stop in which a plurality of openings are arranged eccentrically for the modified light source method (two of these are shown in FIG. 1). Only the aperture stop is shown). The illumination system aperture stop plate 24 is rotated by a drive device 40 such as a motor controlled by the main control device 50, whereby any aperture stop is selectively placed on the optical path of the illumination light EL. The light source surface shape in Koehler illumination, which will be described later, is limited to an annular zone, a small circle, a large circle, or the fourth.

  In place of or in combination with the aperture stop plate 24, for example, a plurality of diffractive optical elements that are exchanged and disposed in the illumination optical system that distributes illumination light to different regions on the pupil plane of the illumination optical system, A plurality of prisms (conical prisms, polyhedral prisms, etc.) having at least one movable along the optical axis IX of the illumination optical system, that is, a variable interval in the optical axis direction of the illumination optical system, and at least one of the zoom optical system; An optical unit including the optical unit 22 is disposed between the light source 16 and the optical integrator 22. When the optical integrator 22 is a fly-eye lens, the intensity distribution of illumination light on the incident surface, and the optical integrator 22 is an internal reflection type integrator. In some cases, illumination optics can be changed by changing the incident angle range of the illumination light to the incident surface. Light amount distribution of the illumination light on the pupil plane of the (size and shape of the secondary light source), i.e. it is desirable to suppress the loss of light due to a change of the illumination condition of the reticle R. In the present embodiment, a plurality of light source images (virtual images) formed by the internal reflection type integrator are also called secondary light sources.

  A relay optical system including a first relay lens 28A and a second relay lens 28B is disposed on the optical path of the illumination light EL emitted from the illumination system aperture stop plate 24 with a reticle blind 30 interposed therebetween. The reticle blind 30 is disposed on a conjugate plane with respect to the pattern surface of the reticle R, and a rectangular opening that defines a rectangular illumination area IAR on the reticle R is formed. Here, as the reticle blind 30, a movable blind having a variable opening shape is used, and the opening is set by the main controller 50 based on blind setting information also called masking information.

  On the optical path of the illumination light EL behind the second relay lens 28B constituting the relay optical system, a bending mirror M that reflects the illumination light EL that has passed through the second relay lens 28B toward the reticle R is disposed. A condenser lens 32 is disposed on the optical path of the illumination light EL behind the mirror M.

  In the above configuration, the entrance surface of the fly-eye lens 22, the placement surface of the reticle blind 30, and the pattern surface of the reticle R are optically conjugate with each other and formed on the exit-side focal plane of the fly-eye lens 22. The light source plane (pupil plane of the illumination optical system) and the Fourier transform plane (exit pupil plane) of the projection optical system PL are optically conjugate with each other to form a Koehler illumination system.

  The operation of the illumination system configured in this way will be briefly described. After the laser beam LB pulsed from the light source 16 is incident on the beam shaping / illuminance equalizing optical system 20 and the cross-sectional shape is shaped, The light enters the fly eye lens 22. Thereby, the secondary light source described above is formed on the exit-side focal plane of the fly-eye lens 22.

  The illumination light EL emitted from the secondary light source passes through any one of the aperture stops on the illumination system aperture stop plate 24, and then passes through the rectangular opening of the reticle blind 30 via the first relay lens 28A. After passing through the second relay lens 28B, the optical path is bent vertically downward by the mirror M, and then through the condenser lens 32, the rectangular illumination area IAR on the reticle R held on the reticle stage RST is uniformly illuminated. Illuminate with.

  A reticle R is loaded on the reticle stage RST, and is held by suction via an electrostatic chuck (or vacuum chuck) (not shown). Reticle stage RST is configured to be capable of minute driving (including rotation) in a horizontal plane (XY plane) by a drive system (not shown). Note that the position of the reticle stage RST is measured by a position detector (not shown) such as a reticle laser interferometer with a predetermined resolution (for example, a resolution of about 0.5 to 1 nm), and the measurement result is sent to the main controller 50. It comes to be supplied.

The material used for the reticle R needs to be properly used depending on the light source used. That is, when an ArF excimer laser or a KrF excimer laser is used as a light source, fluoride crystals such as synthetic quartz and fluorite, or fluorine-doped quartz can be used. However, when an F ₂ laser is used, fluorite is used. It is necessary to form with fluoride crystals such as fluorine-doped quartz.

  As the projection optical system PL, for example, a double telecentric reduction system is used. The projection magnification of the projection optical system PL is, for example, 1/4, 1/5, or 1/6. Therefore, as described above, when the illumination area IAR on the reticle R is illuminated by the illumination light EL, an image obtained by reducing the pattern formed on the reticle R by the projection optical system PL at the projection magnification is the surface. And projected onto a rectangular exposure area IA (usually coincident with the shot area) on the wafer W coated with a resist (photosensitive agent).

As the projection optical system PL, as shown in FIG. 2, a refraction system including only a plurality of, for example, about 10 to 20 refractive optical elements (lens elements) 13 is used. Of a plurality of lens elements 13 that constitute the projection optical system PL, a plurality of the object plane side (reticle R side) (here, five in order to simplify the description) lens elements 13 _1, Reference numerals 13 ₂ , 13 ₃ , 13 ₄ , and 13 ₅ are movable lenses that can be driven from the outside by the imaging performance correction controller 48. The lens elements 13 _{1 to} 13 ₅ are held by the lens barrel via respective double structure lens holders (not shown). These lens elements 13 _{1 to} 13 ₅ are respectively held by the inner lens holder, and these inner lens holders are supported by the driving element (not shown) such as a piezo element with respect to the outer lens holder at three points in the gravitational direction. Yes. By independently adjusting the voltages applied to these drive elements, shift driving each of the lens elements _{131-134 5} in the Z axis direction is the optical axis direction of the projection optical system PL, and the inclination with respect to the XY plane It can be driven (tilted) in a direction (that is, a rotation direction (θx) around the X axis and a rotation direction (θy) around the Y axis).

The other lens elements 13 are held by the lens barrel via a normal lens holder. Not only the lens elements 13 _{1 to} 13 _5, but also aberrations that correct aberrations of the lens disposed in the vicinity of the pupil plane of the projection optical system PL or near the image plane, or the projection optical system PL, in particular, non-rotationally symmetric components. A correction plate (optical plate) or the like may be driven. Furthermore, the degrees of freedom (movable directions) of these drivable optical elements are not limited to three, but may be one, two, or four or more.

  Further, a pupil aperture stop 15 capable of continuously changing the numerical aperture (NA) within a predetermined range is provided in the vicinity of the pupil plane of the projection optical system PL. As this pupil aperture stop 15, for example, a so-called iris stop is used. The pupil aperture stop 15 is controlled by the main controller 50.

When ArF excimer laser light or KrF excimer laser light is used as the illumination light EL, each lens element constituting the projection optical system PL is composed of fluoride crystals such as fluorite and the above-described fluorine-doped quartz. Quartz can also be used, but when F ₂ laser light is used, the materials of the lenses used in the projection optical system PL are all fluoride crystals such as fluorite and fluorine-doped quartz.

  Wafer stage WST is freely driven in an XY two-dimensional plane by a wafer stage driving unit 56 including a linear motor and the like. On the Z tilt stage 58 mounted on the wafer stage WST, the wafer W is held by electrostatic chucking (or vacuum chucking) or the like via a wafer holder (not shown).

  The Z tilt stage 58 is positioned on the wafer stage WST in the XY direction, and is moved in the Z axis direction by an unillustrated drive system and tilted with respect to the XY plane (that is, the rotational direction (θx) around the X axis) and Y It is configured to be drivable (tiltable) in the rotation direction (θy) around the axis. Thereby, the surface position (Z-axis direction position and inclination with respect to the XY plane) of the wafer W held on the Z tilt stage 58 is set to a desired state.

  Further, a movable mirror 52W is fixed on the Z tilt stage 58, and an X-axis direction, a Y-axis direction, and a θz direction (rotation direction about the Z axis) of the Z tilt stage 58 are performed by a wafer laser interferometer 54W arranged outside. The position information measured by the interferometer 54W is supplied to the main controller 50. Main controller 50 determines wafer stage WST via wafer stage drive unit 56 (including all of the drive system of wafer stage WST and the drive system of Z tilt stage 58) based on the measurement value of interferometer 54W. (And Z tilt stage 58) is controlled. Instead of providing the movable mirror 52W, for example, a reflection surface formed by mirror-processing the end surface (side surface) of the Z tilt stage 58 may be used.

  Further, on the Z tilt stage 58, a reference mark plate FM on which a reference mark such as a so-called baseline measurement reference mark of an alignment system ALG described later is formed has a surface substantially the same height as the surface of the wafer W. It is fixed to become.

  A wavefront aberration measuring instrument 80 as a detachable portable wavefront measuring device is attached to the side surface of the Z tilt stage 58 on the + X side (the right side in the drawing in FIG. 2).

  As shown in FIG. 3, the wavefront aberration measuring instrument 80 includes a hollow casing 82 and a light receiving optical system 84 including a plurality of optical elements arranged in a predetermined positional relationship inside the casing 82. And a light receiving portion 86 disposed at the + Y side end portion inside the housing 82.

  The housing 82 is made of a member having an L-shaped YZ cross section and a space formed therein, and light from above the housing 82 is exposed to the internal space of the housing 82 at the uppermost portion (the end in the + Z direction). A circular opening 82a in a plan view (viewed from above) is formed so as to be incident toward. A cover glass 88 is provided so as to cover the opening 82 a from the inside of the housing 82. On the upper surface of the cover glass 88, a light shielding film having a circular opening in the center is formed by vapor deposition of a metal such as chromium, and the light shielding film is unnecessary from the surroundings when measuring the wavefront aberration of the projection optical system PL. Light is blocked from entering the light receiving optical system 84.

  The light receiving optical system 84 is arranged in order from the top to the bottom below the cover glass 88 inside the housing 82, and is placed on the + Y side of the folding mirror 84c. The objective lens 84a, the relay lens 84b, the folding mirror 84c are arranged. A collimator lens 84d and a microlens array 84e are sequentially arranged. The folding mirror 84c is obliquely inclined at 45 °, and the optical path of light incident on the objective lens 84a vertically downward from above is bent by the folding mirror 84c toward the collimator lens 84d. . Each optical member constituting the light receiving optical system 84 is fixed to the inside of the wall of the housing 82 via a holding member (not shown). The microlens array 84e is configured by arranging a plurality of small convex lenses (lens elements) in an array in a plane orthogonal to the optical path.

  The light receiving unit 86 is composed of a light receiving element such as a two-dimensional CCD and an electric circuit such as a charge transfer control circuit. The light receiving element has a sufficient area to receive all of the light beams incident on the objective lens 84a and emitted from the microlens array 84e. Note that the measurement data obtained by the light receiving unit 86 is output to the main controller 50 via a signal line (not shown) or by wireless transmission.

  By using the wavefront aberration measuring instrument 80 described above, the wavefront aberration of the projection optical system PL can be measured on-body. A method for measuring the wavefront aberration of the projection optical system PL using the wavefront aberration measuring instrument 80 will be described later.

Returning to FIG. 2, the exposure apparatus 922 ₁ of this embodiment has a light source that is controlled to be turned on and off by the main controller 50, and has a large number of pinholes or slits toward the image plane of the projection optical system PL. An irradiation system 60a that irradiates an image forming light beam for forming the image of the image from an oblique direction with respect to the optical axis AX, and a light receiving system 60b that receives a reflected light beam on the surface of the wafer W of the image forming light beam. An incident-type multipoint focal position detection system (hereinafter simply referred to as “focus detection system”) is provided. As the focus detection system (60a, 60b), for example, one having the same configuration as that disclosed in Japanese Patent Laid-Open No. 5-275313 and US Pat. No. 5,502,311 corresponding thereto is used.

  The main controller 50 tilts the wafer W with respect to the Z position and the XY plane so that the focus shift becomes zero based on a defocus signal (defocus signal) from the light receiving system 60b, for example, an S curve signal, during exposure or the like. Are controlled via the wafer stage drive unit 56, thereby performing autofocus (automatic focusing) and autoleveling. In addition, the main controller 50 measures and aligns the Z position of the wavefront aberration measuring instrument 80 using the focus detection system (60a, 60b) when measuring the wavefront aberration described later. At this time, the inclination measurement of the wavefront aberration measuring instrument 80 may be performed as necessary.

Further, the exposure apparatus 922 ₁ is an off-axis method used for position measurement of the alignment mark on the wafer W held on the wafer stage WST and the reference mark formed on the reference mark plate FM. The alignment system ALG is provided. As this alignment system ALG, for example, the target mark is irradiated with a broadband detection light beam that does not sensitize the resist on the wafer, and the target mark image formed on the light receiving surface by the reflected light from the target mark and an index (not shown) An image processing type FIA (Field Image Alignment) type sensor that captures the image of the image using an image sensor (CCD or the like) and outputs the imaged signals is used. In addition to the FIA system, the target mark is irradiated with coherent detection light to detect scattered light or diffracted light generated from the target mark, or two diffracted lights (for example, of the same order) generated from the target mark. Of course, it is possible to use an alignment sensor that detects the interference by interfering with each other singly or in an appropriate combination.

Further, in exposure apparatus 922 ₁ of the present embodiment, although not shown, above the reticle R, and the reference mark on the reference mark plate and the corresponding reticle marks on the reticle R through the projection optical system PL A pair of reticle alignment systems including a TTR (Through The Reticle) alignment optical system using light of an exposure wavelength for simultaneously observing the light is provided. In this embodiment, the wafer alignment system ALG and the reticle alignment system have the same configurations as those disclosed in, for example, Japanese Patent Laid-Open No. 6-97031 and US Pat. No. 6,198,527 corresponding thereto. It is used.

  The control system is mainly configured by the main controller 50 in FIG. The main controller 50 includes a so-called workstation (or microcomputer) including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In addition to performing the above control operation, the entire apparatus is controlled in an integrated manner. Main controller 50 controls, for example, step-to-shot stepping of wafer stage WST, exposure timing, and the like so that the exposure operation is performed accurately.

  The main controller 50 includes, for example, a storage device 42 composed of a hard disk, an input device 45 including a pointing device such as a keyboard and a mouse, a display device 44 such as a CRT display (or liquid crystal display), and a CD. A drive device 46 of an information recording medium such as (compact disc), DVD (digital versatile disc), MO (magneto-optical disc) or FD (flexible disc) is connected externally. Further, the main controller 50 is connected to the LAN 918 described above.

  The storage device 42 is a single projection optical system PL measured by a wavefront aberration measuring instrument called a PMI (Phase Measurement Interferometer), for example, before the projection optical system PL is incorporated into the exposure apparatus main body in the manufacturing stage of the exposure apparatus. Measurement data of the wavefront aberration (hereinafter referred to as “single wavefront aberration”) is stored.

Further, in this storage device 42, the projection image formed on the wafer W by the projection optical system PL, for example, is optimally formed under a plurality of reference exposure conditions as will be described later (for example, the aberration is zero or an allowable value). In the state in which the position of each of the aforementioned movable lenses 13 _{1 to} 13 _{5 in} the three degrees of freedom direction, the Z position and tilt of the wafer W (Z tilt stage 58), and the wavelength λ of the illumination light are adjusted so that , Wavefront aberration data measured by the wavefront aberration measuring instrument 80 or wavefront aberration correction amount data (difference between the wavefront aberration and the above-mentioned single wavefront aberration), and information on the adjustment amount at that time, that is, the movable lens 13 ₁ to. 13 ₅ each stores position information in the direction of three degrees of freedom, position information of the wafer W in the direction of three degrees of freedom, and information on the wavelength of the illumination light. Here, since each of the above-described exposure conditions serving as the reference is managed by ID as identification information, hereinafter, each reference exposure condition is referred to as a reference ID. That is, the storage device stores adjustment amount information, wavefront aberration, or wavefront aberration correction amount data for a plurality of reference IDs.

  The positional deviation amount measured by using the wavefront aberration measuring instrument 80 as described later on an information recording medium (in the following description, a CD-ROM for convenience) set in the drive device 46 is used for each term of the Zernike polynomial. Stores a conversion program for conversion into coefficients.

The second and third exposure apparatuses 922 ₂ and 922 ₃ are configured in the same manner as the first exposure apparatus 922 ₁ described above.

Next, a description will be given first to third measuring methods of the wavefront aberration in the exposure apparatus 922 _{1 to 922 3} to be performed, such as during maintenance. In the following description, for simplification of description, it is assumed that the aberration of the light receiving optical system 84 in the wavefront aberration measuring instrument 80 is negligibly small.

  It is assumed that the conversion program in the CD-ROM set in the drive device 46 is installed in the storage device 42.

  During normal exposure, the wavefront aberration measuring instrument 80 is removed from the Z tilt stage 58. Therefore, when measuring the wavefront, first, an operator or a service engineer (hereinafter referred to as “operator etc.” as appropriate) Z tilt stage 58. An operation of attaching the wavefront aberration measuring instrument 80 to the side surface of the lens is performed. At the time of mounting, a bolt or a magnet or the like is provided on a predetermined reference surface (here, the + X side surface) so that the wavefront aberration measuring instrument 80 is within the moving stroke of the wafer stage WST (Z tilt stage 58) during wavefront measurement. Fixed through.

  After completion of the above attachment, in response to an input of a measurement start command by an operator or the like, main controller 50 passes wafer stage drive unit 56 so that wavefront aberration measuring instrument 80 is positioned below alignment system ALG. To move wafer stage WST. Then, main controller 50 detects an alignment mark (not shown) provided in wavefront aberration measuring instrument 80 by alignment system ALG, and positions based on the detection result and the measured value of laser interferometer 54W at that time. The position coordinates of the alignment mark are calculated, and the exact position of the wavefront aberration measuring instrument 80 is obtained. Then, after measuring the position of the wavefront aberration measuring instrument 80, the main controller 50 measures the wavefront aberration as follows.

  First, main controller 50 loads a measurement reticle (not shown) on which a pinhole pattern is formed by a reticle loader (not shown) (hereinafter referred to as “pinhole reticle”) onto reticle stage RST. This pinhole reticle is a reticle in which pinholes (pinholes that generate a spherical wave as an almost ideal point light source) are formed at a plurality of points in the same area as the illumination area IAR of the pattern surface.

  The pinhole reticle used here is provided with a diffusion surface on the upper surface, for example, so that light from the pinhole pattern is distributed over almost the entire pupil plane of the projection optical system PL. It is assumed that wavefront aberration is measured over the entire pupil surface. In this embodiment, since the aperture stop 15 is provided in the vicinity of the pupil plane of the projection optical system PL, the wavefront aberration is measured at the pupil plane substantially defined by the aperture stop 15.

  After loading the pinhole reticle, main controller 50 detects the reticle alignment mark formed on the pinhole reticle using the above-described reticle alignment system, and places the pinhole reticle at a predetermined position based on the detection result. Align to. Thereby, the center of the pinhole reticle and the optical axis of the projection optical system PL substantially coincide.

  Thereafter, the main controller 50 gives the control information TS to the light source 16 to emit the laser beam LB. Thereby, the illumination light EL from the illumination optical system 12 is irradiated to the pinhole reticle. Then, light emitted from a plurality of pinholes of the pinhole reticle is condensed on the image plane via the projection optical system PL, and an image of the pinhole is formed on the image plane.

Next, the main controller 50 sets the opening 82a of the wavefront aberration measuring instrument 80 at an image formation point where an image of any pinhole on the pinhole reticle (hereinafter referred to as a pinhole of interest) is formed. Wafer stage WST is moved via wafer stage drive unit 56 while monitoring the measurement value of wafer laser interferometer 54W so that the centers substantially coincide. At this time, in the main controller 50, based on the detection result of the focus detection system (60a, 60b), the upper surface of the cover glass 88 of the wavefront aberration measuring instrument 80 should be aligned with the image plane on which the pinhole image is formed. The Z tilt stage 58 is slightly driven in the Z-axis direction via the wafer stage drive unit 56. At this time, the tilt angle of the Z tilt stage 58 is also adjusted as necessary. As a result, the image light beam of the pinhole of interest enters the light receiving optical system 84 through the central opening of the cover glass 88 and is received by the light receiving element constituting the light receiving unit 86.

  More specifically, a spherical wave is generated from a focused pinhole on the pinhole reticle, and this spherical wave forms an objective lens constituting the projection optical system PL and the light receiving optical system 84 of the wavefront aberration measuring instrument 80. 84a, relay lens 84b, mirror 84c, and collimator lens 84d are converted into parallel light fluxes to irradiate the microlens array 84e. Thereby, the pupil plane of the projection optical system PL is relayed to the microlens array 84e and divided. Then, each light (divided light) is condensed on the light receiving surface of the light receiving element by each lens element of the microlens array 84e, and a pinhole image is formed on the light receiving surface.

  At this time, if the projection optical system PL is an ideal optical system without wavefront aberration, the wavefront on the pupil plane of the projection optical system PL becomes an ideal wavefront (here, a plane), and as a result, a microlens array. The parallel light flux incident on 84e becomes a plane wave, and its wavefront should be an ideal wavefront. In this case, as shown in FIG. 4A, a spot image (hereinafter also referred to as “spot”) is formed at a position on the optical axis of each lens element constituting the microlens array 84e.

  However, since there is usually wavefront aberration in the projection optical system PL, the wavefront of the parallel light beam incident on the microlens array 84e deviates from the ideal wavefront, and the deviation, that is, the inclination of the wavefront with respect to the ideal wavefront, As shown in FIG. 4B, the image forming position of each spot is shifted from the position on the optical axis of each lens element of the microlens array 84e. In this case, the position shift from the reference point of each spot (the position on the optical axis of each lens element) corresponds to the inclination of the wavefront.

Then, the light (spot image light flux) incident on each light condensing point on the light receiving element constituting the light receiving unit 86 is photoelectrically converted by the light receiving element, and the photoelectric conversion signal is transmitted to the main controller 50 via the electric circuit. Sent. The main controller 50 calculates the imaging position of each spot based on the photoelectric conversion signal, and further calculates the positional deviation (Δξ, Δη) using the calculation result and the position data of a known reference point. And stored in the RAM. At this time, the measurement values (X _i , Y _i ) of the laser interferometer 54W at that time are supplied to the main controller 50.

  As described above, when the measurement of the positional deviation of the spot image by the wavefront aberration measuring device 80 at the focusing point of one focused pinhole image is completed, the main controller 50 forms the next pinhole image. Wafer stage WST is moved so that the substantially center of opening 82a of wavefront aberration measuring instrument 80 coincides with the point. When this movement is completed, the main controller 50 emits the laser beam LB from the light source 16 in the same manner as described above, and the main controller 50 similarly calculates the imaging position of each spot. Thereafter, the same measurement is sequentially performed at other imaging points of the pinhole image.

In this way, at the stage where necessary measurement is completed, the RAM of the main controller 50 stores the above-described positional deviation data (Δξ, Δη) at the image formation point of each pinhole image and the coordinates of each image formation point. Data (measured values (X _i , Y _i ) of the laser interferometer 54W when measurement is performed at the image formation point of each pinhole image) is stored. In addition, for example, for each pinhole, the reticle blind 30 is used at the time of measurement so that only the focused pinhole on the reticle or at least a partial region including the focused pinhole is illuminated with the illumination light EL. The position and size of the illumination area on the reticle may be changed.

Next, the main controller 50 loads the conversion program into the main memory, and the positional deviation data (Δξ, Δη) at the image point of each pinhole image stored in the RAM and the coordinates of each image point. Based on the data, wavefronts (wavefront aberrations) corresponding to the pinhole image forming points according to the principle described below, that is, corresponding to the first to nth measurement points in the field of the projection optical system PL, respectively. here, calculates the coefficient of each term of the Zernike polynomial of equation (3) described below, for example, the coefficients Z ₃₇ coefficient Z ₁ ~ paragraph 37 of the first term in accordance with the conversion program.

  In the present embodiment, the wavefront of the projection optical system PL is obtained by calculation according to the conversion program based on the above-described positional deviations (Δξ, Δη). That is, the positional deviation (Δξ, Δη) is a value that directly reflects the inclination of the wavefront with respect to the ideal wavefront, and conversely, the wavefront can be restored based on the positional deviation (Δξ, Δη). As is clear from the physical relationship between the positional deviations (Δξ, Δη) and the wavefront, the wavefront calculation principle in this embodiment is the well-known Shack-Hartmann wavefront calculation principle.

  Next, a method for calculating the wavefront based on the above positional deviation will be briefly described.

  As described above, the positional deviation (Δξ, Δη) corresponds to the inclination of the wavefront, and by integrating this, the shape of the wavefront (strictly, the deviation from the reference plane (ideal wavefront)) is obtained. When the wavefront (deviation of the wavefront from the reference plane) is W (x, y) and the proportionality coefficient is k, the following relational expressions (1) and (2) are established.

スポット位置のみでしか与えられていない波面の傾きをそのまま積分するのは容易ではないため、面形状を級数に展開して、これにフィットするものとする。この場合、級数は直交系を選ぶものとする。ツェルニケ多項式は軸対称な面の展開に適した級数で、円周方向は三角級数に展開する。すなわち、波面Ｗを極座標系（ρ，θ）で表すと、次式（３）のように展開できる。

Since it is not easy to integrate the slope of the wavefront given only by the spot position as it is, the surface shape is developed into a series and fitted to this. In this case, an orthogonal system is selected as the series. The Zernike polynomial is a series suitable for expansion of an axisymmetric surface, and the circumferential direction is expanded to a triangular series. That is, when the wavefront W is expressed in the polar coordinate system (ρ, θ), it can be developed as the following equation (3).

直交系であるから各項の係数Ｚ_iを独立に決定することができる。ｉを適当な値で切ることはある種のフィルタリングを行うことに対応する。なお、一例として第１項〜第３７項までのｆ_iをＺ_iとともに例示すると、次の表１のようになる。但し、表１中の第３７項は、実際のツェルニケ多項式では、第４９項に相当するが、本明細書では、ｉ＝３７の項（第３７項）として取り扱うものとする。すなわち、本発明において、ツェルニケ多項式の項の数は、特に限定されるものではない。

Since it is an orthogonal system, the coefficient Z _i of each term can be determined independently. Cutting i by an appropriate value corresponds to performing some kind of filtering. As an example, f _i from the first term to the 37th term is illustrated together with Z _i as shown in Table 1 below. However, the 37th term in Table 1 corresponds to the 49th term in the actual Zernike polynomial, but is treated as a term of i = 37 (the 37th term) in this specification. That is, in the present invention, the number of terms of the Zernike polynomial is not particularly limited.

実際には、その微分が上記の位置ずれとして検出されるので、フィッティングは微係数について行う必要がある。極座標系（ｘ＝ρｃｏｓθ，ｙ＝ρｓｉｎθ）では、次式（４）、（５）のように表される。

Actually, since the differentiation is detected as the above-described positional deviation, the fitting needs to be performed on the derivative. In the polar coordinate system (x = ρcos θ, y = ρsin θ), the following expressions (4) and (5) are used.

ツェルニケ多項式の微分形は直交系ではないので、フィッティングは最小自乗法で行う必要がある。１つのスポット像の結像点の情報（ずれ量）はＸ方向とＹ方向につき与えられるので、ピンホールの数をｎ（ｎは、例えば８１〜４００程度とする）とすると、上記式（１）〜（５）で与えられる観測方程式の数は２ｎ（＝１６２〜８００程度）となる。

Since the differential form of the Zernike polynomial is not an orthogonal system, the fitting must be performed by the method of least squares. Since the information (deviation amount) of the image point of one spot image is given in the X direction and the Y direction, when the number of pinholes is n (n is about 81 to 400, for example), the above formula (1 ) To (5), the number of observation equations is 2n (= about 162 to 800).

  Each term in the Zernike polynomial corresponds to an optical aberration. Moreover, the low-order terms (terms with a small i) substantially correspond to Seidel aberration. By using the Zernike polynomial, the wavefront aberration of the projection optical system PL can be obtained.

The calculation procedure of the conversion program is determined according to the principle as described above, and the wavefront corresponding to the first measurement point to the nth measurement point in the field of the projection optical system PL is calculated by the calculation process according to the conversion program. information (wavefront aberration), where the coefficients of the terms of the Zernike polynomial, for example, the first term of the coefficient Z ₁ ~ paragraph 37 of coefficient Z ₃₇ is obtained.

Returning to FIG. 1, target information to be achieved by the _first to third exposure apparatuses 922 _{1 to} 922 ₃ , for example, resolution (resolution), practical minimum line width (device) Rule), the wavelength of illumination light EL (center wavelength and wavelength width, etc.), information on the pattern to be transferred, and other information related to the projection optical system that determines the performance of other exposure apparatuses 922 _{1 to} 922 ₃ , which is the target value The information to get is stored. Further, in the hard disk or the like provided in the first communication server 920, target information in an exposure apparatus scheduled to be introduced in the future, for example, information on a pattern planned to be used is stored as target information.

  On the other hand, an optimization program that optimizes the formation state of a pattern projection image on an object under an arbitrary target exposure condition is installed in a storage device such as a hard disk included in the second communication server 930. In addition, a first database and a second database attached to the optimization program are stored. That is, the optimization program, the first database, and the second database are recorded on an information recording medium such as a CD-ROM, and the information recording medium is a CD-ROM drive provided in the second communication server 930 or the like. The optimization program is installed in a storage device such as a hard disk, and the first database and the second database are copied from the drive device.

The first database is a database of wavefront aberration change tables for each type of projection optical system (projection lens) provided in an exposure apparatus such as the exposure apparatuses 922 _{1 to} 922 ₃ . Here, the wavefront aberration change table is simulated using a model substantially equivalent to the projection optical system PL, and the formation state of the pattern projection image on the object obtained as a result of the simulation is optimized. Change of the unit adjustment amount of the adjustment parameter that can be used to convert the image, and imaging performance corresponding to each of a plurality of measurement points in the field of the projection optical system PL, specifically, wavefront data, for example, the first of the Zernike polynomial It is a change table which consists of the data group which arranged the data which show the relationship with the variation | change_quantity of the coefficient of a term-the 37th term according to the predetermined rule.

In the present embodiment, the adjustment parameters include the drive amounts z ₁ , θx ₁ , θy ₁ of the movable lenses 13 ₁ , 13 ₂ , 13 ₃ , 13 ₄ , 13 _{5 in} the respective degrees of freedom directions (directions in which they can be driven). , Z ₂ , θx ₂ , θy ₂ , z ₃ , θx ₃ , θy ₃ , z ₄ , θx ₄ , θy ₄ , z ₅ , θx ₅ , θy ₅ and the wafer W surface (Z tilt stage 58) A total of 19 parameters are used, such as the drive amount Wz, Wθx, Wθy in the direction of the angle and the wavelength shift amount Δλ of the illumination light EL.

  Here, a procedure for creating this database will be briefly described. First, the design value of the projection optical system PL (numerical aperture NA, coherence factor σ value, illumination light wavelength λ, data of each lens, etc.) is input to a simulation computer in which specific optical software is installed. To do. Next, data of an arbitrary first measurement point in the visual field of the projection optical system PL is input to the simulation computer.

Next, unit amount data for each of the degrees of freedom (movable direction) of the movable lenses 13 _{1 to} 13 ₅ , each of the degrees of freedom of the surface of the wafer W, and the shift amount of the wavelength of the illumination light is input. For example, if you enter a command that the movable lens 13 ₁ is driven by a unit amount with respect to the + direction of the Z-direction shift, the simulation computer, the first wave front of the first measurement point determined in advance within the field of projection optical system PL Data on the amount of change from the ideal wavefront, for example, the amount of change in the coefficient of each term (for example, the first to 37th terms) of the Zernike polynomial is calculated, and the data on the amount of change is displayed on the display screen of the simulation computer. At the same time, the amount of change is stored in the memory as a parameter PARA1P1.

Then, if you enter a command that the movable lens 13 ₁ is driven by a unit amount with respect to the + direction of the Y-direction tilt (x-axis of rotation [theta] x), the simulation computer, the second wavefront data for the first measurement point, For example, the change amount of the coefficient of each term of the Zernike polynomial is calculated, the change amount data is displayed on the display screen, and the change amount is stored in the memory as the parameter PARA2P1.

Then, if you enter a command that the movable lens 13 ₁ is driven by a unit amount with respect to the + direction of the X-direction tilt (y-axis of rotation [theta] y), the simulation computer, third wavefront data for the first measurement point, For example, the change amount of the coefficient of each term of the Zernike polynomial is calculated, and the change amount data is displayed on the screen of the display, and the change amount is stored in the memory as the parameter PARA3P1.

Thereafter, in the same procedure as above, the input of each measurement point to the second measurement point through n th measurement point is performed, Z-direction shift of the movable lens 13 _1, Y-direction tilt command input X-direction tilt respectively Each time the simulation is performed, the simulation computer calculates the first wavefront, second wavefront, and third wavefront data at each measurement point, for example, the amount of change in the coefficient of each term in the Zernike polynomial, and the amount of change data is calculated. In addition to being displayed on the display screen, parameters PARA1P2, PARA2P2, PARA3P2,..., PARA1Pn, PARA2Pn, PARA3Pn are stored in the memory.

For the other movable lenses 13 ₂ , 13 ₃ , 13 ₄ , and 13 ₅ , the input of each measurement point and the command input for driving in the + direction by the unit amount with respect to each direction of freedom are performed in the same procedure as described above. In response to this, each of the first to n-th measurement points when the movable lenses 13 ₂ , 13 ₃ , 13 ₄ , and 13 ₅ are driven by a unit amount in the directions of degrees of freedom by the simulation computer. , For example, the amount of change in the coefficient of each term of the Zernike polynomial is calculated, parameters (PARA4P1, PARA5P1, PARA6P1,..., PARA15P1), parameters (PARA4P2, PARA5P2, PARA6P2,..., PARA15P2),. , Parameters (PARA4Pn, PARA5Pn, PARA6Pn, ..., PARA15Pn) Stored in memory.

Also for wafer W, in the same procedure as described above, input of each measurement point and command input for driving in the + direction by a unit amount for each direction of freedom are performed. Wavefront data for each of the first to nth measurement points when the wafer W is driven by a unit amount in each direction of freedom of Z, θx, θy by a computer, for example, the amount of change in the coefficient of each term of the Zernike polynomial Are calculated, and parameters (PARA16P1, PARA17P1, PARA18P1), parameters (PARA16P2, PARA17P2, PARA18P2),..., Parameters (PARA16Pn, PARA17Pn, PARA18Pn) are stored in the memory.

Further, with respect to wavelength shift, in the same procedure as described above, input of each measurement point and command input for shifting the wavelength in the + direction by the unit amount are performed, and in response to this, the wavelength is shifted by the simulation computer. Wavefront data for each of the first to n-th measurement points when the value is shifted by a unit amount in the + direction, for example, the amount of change in the coefficient of each term of the Zernike polynomial is calculated, and PARA19P1, PARA19P2,. Stored in memory.

  Here, each of the parameters PARAiPj (i = 1 to 19, j = 1 to n) is a 1 × 37 row matrix (vector). That is, when n = 33, the adjustment parameter PARA1 is expressed by the following equation (6).

また、調整パラメータＰＡＲＡ２について、次式（７）のようになる。

Further, the adjustment parameter PARA2 is expressed by the following equation (7).

同様に、他の調整パラメータＰＡＲＡ３〜ＰＡＲＡ１９についても、次式（８）のようになる。

Similarly, the other adjustment parameters PARA3 to PARA19 are expressed by the following equation (8).

そして、このようにしてメモリ内に記憶されたツェルニケ多項式の各項の係数の変化量から成るＰＡＲＡ１Ｐ１〜ＰＡＲＡ１９Ｐｎは、調整パラメータ毎に纏められ、１９個の調整パラメータ毎の波面収差変化表として並べ替えが行われている。すなわち、次式（９）で調整パラメータＰＡＲＡ１について代表的に示されるような調整パラメータ毎の波面収差変化表が作成され、メモリに内に格納される。

Then, PARA1P1 to PARA19Pn that are composed of the change amounts of the coefficients of the terms of the Zernike polynomial stored in the memory in this way are collected for each adjustment parameter and rearranged as a wavefront aberration change table for each of the 19 adjustment parameters. Has been done. That is, a wavefront aberration change table for each adjustment parameter as representatively shown for the adjustment parameter PARA1 in the following equation (9) is created and stored in the memory.

そして、このようにして作成された、投影光学系の種類毎の波面収差変化表から成るデータベースが、第１データベースとして、第２通信サーバ９３０が備えるハードディスク等の内部に格納されている。なお、本実施形態では、同一種類（同じ設計データ）の投影光学系では１つの波面収差変化表を作成するものとしたが、その種類に関係なく、投影光学系毎に（すなわち露光装置単位で）波面収差変化表を作成しても良い。

A database composed of the wavefront aberration change table for each type of projection optical system created in this manner is stored as a first database in a hard disk or the like included in the second communication server 930. In this embodiment, one wavefront aberration change table is created for the same type (same design data) of projection optical system. However, regardless of the type of projection optical system, each projection optical system (that is, in units of exposure apparatuses) is used. ) A wavefront aberration change table may be created.

  Next, the second database will be described.

  The second database stores different exposure conditions, that is, optical conditions (exposure wavelength, numerical aperture NA of the projection optical system (maximum NA, NA set during exposure, etc.), and illumination conditions. (Illumination NA (numerical aperture NA of illumination optical system)) or illumination σ (coherence factor), aperture shape of illumination system aperture stop plate 24 (light quantity distribution of illumination light on pupil plane of illumination optical system) That is, the shape of the secondary light source)))), evaluation items (mask type, line width, evaluation amount, pattern information, etc.), and a plurality of exposure conditions determined by a combination of these optical conditions and evaluation items, respectively. A calculation table composed of the amount of change per 1λ in each term of the Zernike polynomial of the imaging performance of the projection optical system, for example, various aberrations (or index values thereof), for example, the first term to the 37th term, that is, Zernike. Sensitivity table (Zernike Sensitivity).

  In the following description, the Zernike sensitivity table is also called Zernike Sensitivity or ZS. In addition, a file including a Zernike sensitivity table under a plurality of exposure conditions is also referred to as a “ZS file” where appropriate.

In the present embodiment, each Zernike sensitivity table includes the following 12 types of aberration as imaging performance, that is, index values of distortion Dis _x and Dis _y in the X-axis direction and Y-axis direction, and four types of coma aberration. Line width abnormal values CM _V , CM _H , CM _R , CM _L , four types of curvature of field CF _V , CF _H , CF _R , CF _L , and two types of spherical aberration SA _V , SA _H , include.

Next, using the aforementioned optimization program for a method of optimizing the formation conditions on the wafer of the projected image of the reticle pattern in such first to third exposure apparatus 922 _{1 to 922 3,} the second communication server The processing algorithm of the processor included in 930 will be described with reference to the flowchart of FIG. 5 (and FIGS. 6 to 10 and FIGS. 14 to 20).

  The flowchart shown in FIG. 5 starts when, for example, an operator of an exposure apparatus in a clean room designates an exposure apparatus (unit) to be optimized by e-mail or the like via the first communication server 920. The optimization instruction is sent, and the operator on the second communication server 930 side inputs the instruction to start processing to the second communication server 930.

  First, in step 102, a target machine designation screen is displayed on the display.

In the next step 104, the system waits for the designation of the number machine, and when the number machine designated by the operator in the previous e-mail, for example, the exposure device 922 ₁ is designated via a pointing device such as a mouse, Proceed to 106 to store the designated number. This machine is stored by storing, for example, the device number.

  In the next step 108, a mode selection screen is displayed on the display. In this embodiment, since any one of mode 1 to mode 3 can be selected, for example, selection buttons for mode 1, mode 2, and mode 3 are displayed on the mode selection screen.

In the next step 110, it waits for a mode to be selected. When the operator selects a mode with the mouse or the like, the process proceeds to step 112 to determine whether or not the selected mode is mode 1. If mode 1 is selected, the process proceeds to a subroutine for performing mode 1 processing in step 118 (hereinafter also referred to as “mode 1 processing routine”). Here, mode 1 is a mode in which optimization is performed based on an existing ID. In this mode 1, the exposure apparatus 922 ₁ is in use after being adjusted under a certain reference exposure condition (reference ID). For example, the illumination condition and the numerical aperture (NA) of the projection optical system are used. This is mainly selected when changing.

In the processing routine of this mode 1 (hereinafter also referred to as “first mode”), first, in step 202 of FIG. 6, the exposure condition to be optimized (hereinafter also referred to as “optimized exposure condition” as appropriate). Get information about. Specifically, the first communication server 920 (or target Unit via the first communication server 920 (exposure apparatus 922 ₁₎ of the main control unit 50), the current projection of the target Unit (exposure apparatus 922 ₁₎ N. of the optical system. A. Inquires and acquires setting information such as illumination conditions (illumination NA or illumination σ, aperture stop type, etc.) and target pattern type.

In the next step 204, for the first communication server 920 (or the main controller 50 of the target number machine (exposure apparatus 922 ₁ ) via the first communication server 920), the reference closest to the optimized exposure condition is set. And the projection optical system N.D. A. And setting information such as illumination conditions (for example, illumination NA or illumination σ, type of aperture stop).

In the next step 206, from the first communication server 920 (or from the main controller 50 of the target machine (exposure device 922 ₁ ) via the first communication server), the necessary information on the single wavefront aberration and the reference ID, specifically, Acquires the value of the adjustment amount (adjustment parameter) in the reference ID, the wavefront aberration correction amount (or information on the imaging performance) for the single wavefront aberration in the reference ID, and the like.

  Here, the wavefront aberration correction amount (or information on the imaging performance) is used to estimate the wavefront aberration correction amount (or wavefront aberration) from the imaging performance when the wavefront aberration correction amount in the reference ID is unknown. Because it can. The estimation of the wavefront aberration correction amount from the imaging performance will be described in detail later.

  Usually, the single wavefront aberration of the projection optical system and the wavefront aberration of the projection optical system PL after being incorporated in the exposure apparatus (hereinafter referred to as on-body wavefront aberration) do not coincide with each other for some reason. For the sake of simplification, it is assumed that this correction is made for each reference ID (reference exposure condition) at the time of starting the exposure apparatus or by adjustment in the manufacturing stage.

In the next step 208, from the first communication server 920 (or the main controller 50 of the target machine (exposure apparatus 922 ₁ ) via the first communication server 920), the model name, exposure wavelength, and maximum N. of the projection optical system. A. Get device information.

  In the next step 210, a ZS file corresponding to the aforementioned optimized exposure condition is searched from the second database.

  In the next step 214, it is determined whether or not a ZS file corresponding to the optimized exposure condition is found. If found, the ZS file is read into a memory such as a RAM. On the other hand, if the determination in step 214 is negative, that is, if the ZS file corresponding to the optimized exposure condition does not exist in the second database, the process proceeds to step 218 and the ZS in the second database. The ZS file is created using a database, for example, by the interpolation method described below.

  Here, this interpolation method will be briefly described using a specific example.

  Zernike Sensitivety (Zernike Sensitivity Table) is the illumination condition, N. of projection optical system. A. Depends on the type of reticle pattern and evaluation items.

  Illumination conditions typically include a light amount distribution (for example, the shape and size of the secondary light source described above) on the pupil plane of the illumination optical system including the illumination σ and the annular ratio.

  In addition, the types of reticle patterns include the type of blank pattern or remaining pattern, the type of dense pattern or isolated pattern, the pitch, line width, duty ratio, and isolated line for dense lines (such as line and space). Line width, vertical width in case of contact hole, horizontal width, distance between hole patterns (pitch, etc.), phase shift pattern (including halftone type) or phase shift reticle and its type (for example, spatial frequency modulation type) , Halftone type).

  The evaluation items include various aberrations such as distortion, abnormal line width (index value of coma aberration), focus (image surface), spherical aberration (focus difference between patterns), and the like. Note that the evaluation items are not limited to these, and any imaging performance (aberration) or index value that can be evaluated by a Zernike polynomial, for example, may be used.

  This interpolation method basically requires two or more known points that can be interpolated. Since there is a problem in terms of accuracy, extrapolation is not performed. Specifically, linear interpolation is performed when there are only two known points. On the other hand, when there are three or more known points, high-precision interpolation such as linear interpolation, polynomial approximation (secondary function, cubic function, etc.), or spline interpolation is performed. Which interpolation method is used is determined by whether or not the rate of change of Zernike Sensitivity (first derivative, second derivative) is large. When the change is monotonous, linear interpolation is performed.

  Further, when there are a plurality of conditions to be interpolated, sequential interpolation is performed.

Hereinafter, as an example, the projection optical system N.I. A. = 0.74, illumination σ (hereinafter also referred to as “σ” as appropriate) = 0.52 If there is no ZS file that matches the condition (however, conditions other than NA and σ match) Line width of 100 nm, isolated line, blank pattern, N. of projection optical system. A. A case will be described in which a ZS file relating to a focus of = 0.74 and illumination σ = 0.52 is created by an interpolation method. In this case, multiple conditions N. A. Zernike Sensitivity interpolation for = 0.74 and σ = 0.52 needs to be performed sequentially.
(1) First, check the points that can be used for interpolation. That is, a ZS file that can be used for interpolation is selected. In this example, three-point interpolation is performed. N. A. A ZS file with 3 points for 3 and 3 points for σ and 3 × 3 = 9 conditions is required. Select 9 ZS files that can be interpolated. That is, here, N. A. Nine ZS files having a value of 0.8, 0.7 or 0.6 and a value of σ of 0.4, 0.5 or 0.6 are selected.
ZS (NA = 0.6, σ = 0.4), ZS (NA = 0.6, σ = 0.5), ZS (NA = 0.6, σ = 0.6)
ZS (NA = 0.7, σ = 0.4), ZS (NA = 0.7, σ = 0.5), ZS (NA = 0.7, σ = 0.6)
ZS (NA = 0.8, σ = 0.4), ZS (NA = 0.8, σ = 0.5), ZS (NA = 0.8, σ = 0.6)
Thereafter, interpolation calculation is performed for each condition in order.
(2) N.R. A. = Interpolation calculation of ZS file for 0.74.

As schematically shown in FIG. A. = 0.74, N. A. When Zernike Sensitivity concerning = 0.6, 0.7, 0.8 is known, quadratic function approximation (or spline interpolation) is performed from these three points. As a result, the ZS file is as follows.
ZS (NA = 0.6, σ = 0.4), ZS (NA = 0.6, σ = 0.5), ZS (NA = 0.6, σ = 0.6)
ZS (NA = 0.7, σ = 0.4), ZS (NA = 0.7, σ = 0.5), ZS (NA = 0.7, σ = 0.6)
ZS (NA = 0.74, σ = 0.4), ZS (NA = 0.74, σ = 0.5), ZS (NA = 0.74, σ = 0.6)
ZS (NA = 0.8, σ = 0.4), ZS (NA = 0.8, σ = 0.5), ZS (NA = 0.8, σ = 0.6)
11 shows the N.P. obtained by this interpolation. A. An approximate curve of 0.74 is indicated by a solid line C1.
(3) Next, the ZS file for σ = 0.52 is calculated by interpolation.

Zernike for σ = 0.4, 0.5, 0.6 near σ = 0.52
When Sensitivity is known, quadratic function approximation (or spline interpolation) is performed from these three points. As a result, the ZS file is as follows.
ZS (NA = 0.6, σ = 0.4), ZS (NA = 0.6, σ = 0.5), ZS (NA = 0.6, σ = 0.52), ZS (NA = 0.6, σ = 0.6)
ZS (NA = 0.7, σ = 0.4), ZS (NA = 0.7, σ = 0.5), ZS (NA = 0.6, σ = 0.52), ZS (NA = 0.7, σ = 0.6)
ZS (NA = 0.74, σ = 0.4), ZS (NA = 0.74, σ = 0.5), ZS (NA = 0.74, σ = 0.52), ZS (NA = 0.74, σ = 0.6)
ZS (NA = 0.8, σ = 0.4), ZS (NA = 0.8, σ = 0.5), ZS (NA = 0.8, σ = 0.52), ZS (NA = 0.8, σ = 0.6)
In FIG. 11, the approximate curve of σ = 0.52 obtained in this way is indicated by a solid line C2.

  As can be seen from FIG. 11, as indicated by the intersections (circles) of the curves C 1 and C 2, the line width to be obtained is 100 nm, the isolated line, the extracted pattern, and the N.I. A. A ZS file relating to the focus of 0.74 and illumination σ 0.52 is created by the interpolation method.

  By adopting a method of creating a new ZS file by this interpolation method, in particular, N.I. A. Because there are continuously variable items such as σ, etc., it is difficult to prepare all ZS files in advance, and there are many combinations of preparing ZS files of all conditions at a fine pitch in advance. The practical problem of being impossible is easily solved.

  In addition, this interpolation method uses N. A. , Lighting σ, zone ratio, pitch (dense line, contact hole), line width (dense line, isolated line), vertical / horizontal width (contact hole), etc. Has been. Furthermore, the interpolation method described above is the distance between the partial area where the intensity distribution of the illumination light on the pupil plane of the illumination optical system is enhanced by modified illumination such as quadrupole illumination and the optical axis of the illumination optical system, or of the partial area. It is also effective in creating a ZS file such as the size (corresponding to the illumination σ).

  Next, in step 220 of FIG. 7, a screen for specifying an allowable value (target value) for imaging performance (the above-mentioned 12 types of aberrations) is displayed on the display, and then whether or not an allowable value is input in step 222. If this determination is negative, the process proceeds to step 226 to determine whether or not a certain period of time has elapsed since the above input screen for the allowable value was displayed, and this determination was negative If yes, return to step 222. On the other hand, if an allowable value is designated by the operator via a keyboard or the like in step 222, the designated aberration allowable value is stored in a memory such as a RAM, and then the process proceeds to step 226. That is, such a loop of step 222 → 226 or a loop of step 222 → 224 → 226 is repeated, and it waits for a predetermined time until an allowable value is designated.

  Here, the allowable value does not necessarily have to be used for the optimization calculation itself (in this embodiment, calculation of the adjustment amount of the adjustment parameter using the merit function Φ as will be described later), but when the calculation result is evaluated, Necessary. Further, in the present embodiment, this allowable value is also required for setting the weight of the imaging performance described later.

  Then, when a certain period of time has passed, the process proceeds to step 228, and an allowable value of the aberration not designated is read from the ZS database in the second database according to the default setting. As a result, the specified aberration tolerance and the remaining aberration tolerance read from the ZS database are stored in the memory.

  In the next step 230, after the constraint condition designation screen is displayed on the display, it is determined whether or not the constraint condition is input in step 232, and if this determination is negative, the process proceeds to step 236. Then, it is determined whether or not a certain period of time has elapsed since the above constraint condition designation screen was displayed. If this determination is denied, the process returns to step 232. On the other hand, if a constraint condition is designated by the operator via the keyboard or the like in step 232, the process proceeds to step 234, and after the constraint condition of the designated adjustment parameter is stored in a memory such as a RAM, Control goes to step 236. That is, such a loop of step 232 → 236 or a loop of step 232 → 234 → 236 is repeated to wait for a predetermined time until the constraint condition is designated.

Here, the constraint conditions are the above-described allowable movable ranges of the movable lenses 13 _{1 to} 13 _{5 in} the respective degrees of freedom, the allowable movable ranges of the Z tilt stage 58 in the three degrees of freedom, the allowable range of wavelength shift, and the like. This means an allowable variable range of each adjustment amount (adjustment parameter).

  Then, when a certain time has elapsed, the process proceeds to step 238, and the movable range calculated based on the current value of each adjustment parameter is calculated as a restriction condition for the adjustment parameter not specified according to the default setting. And stored in a memory such as a RAM. As a result, the restriction conditions for the designated adjustment parameter and the calculated restriction conditions for the remaining adjustment parameters are stored in the memory.

  Next, in step 240 of FIG. 8, an imaging performance weight designation screen is displayed on the display. Here, in the case of this embodiment, the imaging performance weights need to be specified for the above-described 12 types of aberrations for 33 evaluation points (measurement points) in the field of the projection optical system. Therefore, it is necessary to specify 33 × 12 = 396 weights. For this reason, on the weight designation screen, first, a weight designation screen for 12 types of imaging performance is displayed so that weights can be designated in two stages, and then weights are designated at each evaluation point in the field of view. The screen is displayed. Further, an automatic designation selection button is also displayed on the weighting screen for imaging performance.

  In step 242, it is determined whether any imaging performance weight is designated. If the weight is designated by the operator via the keyboard or the like, the process proceeds to step 244 to store the designated imaging performance (aberration) weight in a memory such as a RAM and then proceeds to step 248. . In this step 248, it is determined whether or not a fixed time has elapsed since the start of the display of the above-described weight designation screen. If this determination is negative, the process returns to step 242.

  On the other hand, if the determination in step 242 is negative, the process proceeds to step 246, where it is determined whether automatic designation is selected. If this determination is negative, the process proceeds to step 248. On the other hand, when the operator points the automatic selection button via the mouse or the like, the process proceeds to step 250, and the current imaging performance is calculated based on the following equation (10).

f = Wa · ZS (10)
Here, f is the imaging performance represented by the following equation (11), and Wa is calculated from the single wavefront aberration acquired in step 206 and the wavefront aberration correction amount in the reference ID. It is the data of the wavefront aberration shown by these. ZS is the data of the ZS file represented by the following equation (13) acquired in step 216 or 218.

式（１１）において、ｆ_i,1（ｉ＝１〜３３）は、ｉ番目の計測点におけるDis_x、ｆ_i,2はｉ番目の計測点におけるDis_y、ｆ_i,3はｉ番目の計測点におけるＣＭ_V、ｆ_i,4はｉ番目の計測点におけるＣＭ_H、ｆ_i,5はｉ番目の計測点におけるＣＭ_R、ｆ_i,6はｉ番目の計測点におけるＣＭ_L、ｆ_i,7はｉ番目の計測点におけるＣＦ_V、ｆ_i,8はｉ番目の計測点におけるＣＦ_H、ｆ_i,9はｉ番目の計測点におけるＣＦ_R、ｆ_i,10はｉ番目の計測点におけるＣＦ_L、ｆ_i,11はｉ番目の計測点におけるＳＡ_V、ｆ_i,12はｉ番目の計測点におけるＳＡ_Hを、それぞれ示す。

In Expression (11), f _{i, 1} (i = _{1 to} 33) is Dis _{x at the} i-th measurement point, f _{i, 2} is Dis _{y at the} i-th measurement point, and f _{i, 3} is the i-th measurement point. CM _V and fi _{, 4} at the measurement point are CM _{H at the} i-th measurement point, fi _{, 5} are CM _{R at the} i-th measurement point, and fi _{, 6} are CM _L and fi at the _i- th measurement point. _{, 7} is CF _{V at the} i-th measurement point, f _{i, 8} is CF _{H at the} i-th measurement point, f _{i, 9} is CF _{R at the} i-th measurement point, and fi _{, 10} are the i-th measurement point. CF _L , f _{i, 11 in FIG. 4} indicate SA _{V at the} i-th measurement point, and f _{i, 12} indicate SA _H at the i-th measurement point, respectively.

In equation (12), Z _{i, j} represents the coefficient of the j-th term (j = 1 to 37) of the Zernike polynomial of wavefront aberration at the i-th measurement point.

In the equation (13), b _{p, q} (p = 1 to 37, q = 1 to 12) indicates each element of the ZS file, among which b _{p, 1} is a Zernike polynomial in which wavefront aberration is developed. Change of Dis _x per 1λ of p-term, b _{p, 2} is change of Dis _y per 1λ of p-term, b _{p, 3} is change of CM _V per 1λ of p-term, b _{p, 4} Is the change in CM _H per 1λ of the p term, b _{p, 5} is the change in CM _R per 1λ of the p term, b _{p, 6} is the change in CM _L per 1λ of the p term, b _{p, 7} is the change in CF _V per 1λ of the p term, b _{p, 8} is the change in CF _H per 1λ of the p term, b _{p, 9} is the change in CF _R per 1λ of the p term, b _{p , 10} change in CF _L per 1λ of the p sections, b _{p, 11} changes in SA _V per 1λ of the p sections, b _{p, 12} is a variation of the SA _H per 1λ of the p sections respectively Show.

  In the next step 252, among the calculated 12 types of imaging performance (aberration), the imaging performance weight that exceeds the previously set allowable value is increased (greater than 1), and then the processing proceeds to step 254. Transition. Note that the imaging performance having a large amount that exceeds the allowable value may be displayed in a color-coded manner on the screen. In this way, the operator can assist in specifying the weight of the imaging performance.

  In this embodiment, by repeating the loop of step 242 → 246 → 248 or the loop of step 242 → 244 → 248, the weight of the imaging performance is designated. Wait for a certain time from the start of display. If automatic designation is selected during this period, automatic designation is performed. On the other hand, when automatic designation is not selected, if at least one weight of imaging performance is designated, the designated imaging performance weight is stored. Then, after a certain period of time elapses in this way, the process proceeds to step 253, where the weight of each imaging performance not designated is set to 1 according to the default setting, and then the process proceeds to step 254.

  As a result, the designated imaging performance weight and the remaining imaging performance weight (= 1) are stored in the memory.

In the next step 254, a screen for specifying the weight at the evaluation point (measurement point) in the visual field is displayed on the display, and in step 256, it is determined whether or not the weight at any evaluation point is specified. If the result is negative, the process proceeds to step 260, and it is determined whether or not a certain time has elapsed since the start of the display of the screen for designating the weight at the evaluation point (measurement point). If the determination is negative, the process returns to step 256.

  On the other hand, in step 256, when a weight for one of the evaluation points (usually, an evaluation point for which improvement is particularly desired is selected) is specified by the operator via a keyboard or the like, the process proceeds to step 258, where After setting the weight at the evaluation point and storing it in a memory such as a RAM, the routine proceeds to step 260.

  That is, by repeating the loop of step 256 → 260 or the loop of step 256 → 258 → 260, it waits for a certain period of time from the start of display of the weight designation screen at the above-mentioned evaluation point until the weight of the evaluation point is designated. .

  When the predetermined time has elapsed, the process proceeds to step 262, and the weights at all evaluation points not designated are set to 1 according to the default setting, and then the process proceeds to step 264.

  As a result, the designated value of the weight at the designated evaluation point and the weight (= 1) at the remaining evaluation points are stored in the memory.

  In step 264 of FIG. 9, a screen for specifying a target value (target) of imaging performance (the above-mentioned 12 types of aberrations) at each evaluation point in the field of view is displayed on the display. Here, in the case of this embodiment, the target of imaging performance needs to be specified for the above-described 12 types of aberrations for 33 evaluation points (measurement points) in the field of the projection optical system. It is necessary to specify 33 × 12 = 396 targets. For this reason, on the target designation screen, a setting assistance button is displayed together with a manually designated display portion.

  In the next step 266, waiting for a target to be designated for a predetermined time (that is, determining whether or not the target has been designated), and if no target has been designated (if the judgment is negative), Moving to step 270, it is determined whether or not setting assistance is designated. If the determination is negative, the process proceeds to step 272, where it is determined whether or not a certain time has elapsed since the display of the target designation screen was started. If this determination is negative, the process returns to step 266.

  On the other hand, in step 270, when setting assistance is designated by the operator pointing the setting assistance button with a mouse or the like, the process proceeds to step 276 to execute the aberration decomposition method.

  Here, this aberration decomposition method will be described.

  First, each imaging performance (aberration), which is an element of the imaging performance f described above, is expanded to the power as shown by the following equation (14) for x and y.

f = G · A (14)
In the above equation (14), G is a matrix of 33 rows and 17 columns represented by the following equation (15).

ここで、ｇ₁＝１、ｇ₂＝ｘ、ｇ₃＝ｙ、ｇ₄＝ｘ²、ｇ₅＝ｘｙ、ｇ₆＝ｙ²、ｇ₇＝ｘ³、ｇ₈＝ｘ²ｙ、ｇ₉＝ｘｙ²、ｇ₁₀＝ｙ³、ｇ₁₁＝ｘ⁴、ｇ₁₂＝ｘ³ｙ、ｇ₁₃＝ｘ²ｙ²、ｇ₁₄＝ｘｙ³、ｇ₁₅＝ｙ⁴、ｇ₁₆＝ｘ（ｘ²＋ｙ²）、ｇ₁₇＝ｙ（ｘ²＋ｙ²）である。また、（ｘ_i、ｙ_i）は、第ｉ番目の評価点のｘｙ座標である。

_{Here, g 1 = 1, g 2} = x, g 3 = y, g 4 = x 2, g 5 = xy, g 6 = y 2, g 7 = x 3, g 8 = x 2 y, g 9 _{^{= xy 2, g 10 = y}} 3, g 11 = x 4, g 12 = x 3 y, g 13 = x 2 y 2, g 14 = xy 3, g 15 = y 4, g 16 = x (x 2 + Y ² ), g ₁₇ = y (x ² + y ² ). Further, (x _i , y _i ) is an xy coordinate of the i-th evaluation point.

  Further, in the above equation (14), A is a matrix having 17 rows and 12 columns of decomposition item coefficients represented by the following equation (16) as elements.

上式（１４）を最小自乗法が可能となるように、次式（１７）のように変形する。
Ｇ^T・ｆ＝Ｇ^T・Ｇ・Ａ ……（１７）
ここで、Ｇ^Tは、マトリックスＧの転置行列である。
次に、上式（１７）に基づいて最小自乗法により、マトリックスＡを求める。
Ａ＝（Ｇ^T・Ｇ）^-1・Ｇ^T・ｆ ……（１８）
このようして収差分解法が実行され、分解後の各分解項目係数が求められる。

The above equation (14) is transformed into the following equation (17) so that the least square method is possible.
G ^T · f = G ^T · G · A (17)
Here, G ^T is a transposed matrix of the matrix G.
Next, the matrix A is obtained by the least square method based on the above equation (17).
A = (G ^T · G) ^-1 · G ^T · f (18)
In this way, the aberration decomposition method is executed, and each decomposition item coefficient after the decomposition is obtained.

  Returning to the explanation of FIG. 9, in the next step 278, a screen for specifying the target value of the coefficient is displayed on the display together with the respective decomposition item coefficients after the decomposition obtained as described above.

  In the next step 280, the process waits until target values (targets) of all the decomposition item coefficients are designated. When all the decomposition coefficient targets are specified by the operator via the keyboard or the like, the process proceeds to step 282 to convert the decomposition item coefficient target into an imaging performance target by the following equation (19). In this case, the operator may specify the target by changing only the target of the coefficient to be improved, and may specify the displayed coefficient as the target as it is for the remaining coefficient targets.

f _t = G · A ′ (19)
In the above equation (19), f _t is a target of the designated imaging performance, and A ′ is a matrix whose elements are the designated decomposition item coefficients (after improvement).

  Note that it is not always necessary to display each decomposition item coefficient calculated by the aberration decomposition method on the screen, and based on each calculated decomposition item coefficient, a target of a coefficient that needs improvement is automatically set. It is also possible to do.

  On the other hand, when any one of the imaging performance targets at any of the evaluation points is specified by the operator via the keyboard or the like in step 266, the determination in step 266 is affirmed, and the process proceeds to step 268. After the designated target is set and stored in a memory such as a RAM, the process proceeds to step 272.

  That is, in this embodiment, the target is designated by repeating the loop of step 266 → 270 → 272 or the loop of step 266 → 268 → 272 for a certain time from the start of display of the target designation screen. wait. If setting assistance is specified during this period, target specification is performed in the flow of calculation and display of the decomposition item coefficient and specification of the target of the decomposition item coefficient as described above. When setting assistance is not designated, when one or more imaging performance targets at one or more evaluation points are designated, a designated imaging performance target at the designated evaluation points is selected. Remember. Then, after a certain period of time elapses in this way, the process proceeds to step 274, and after setting all of the imaging performance targets at the evaluation points not designated to 0 according to the default settings, the process proceeds to step 284. To do.

As a result, in the memory, the target of the designated imaging performance at the designated evaluation point and the remaining target (= 0) of the imaging performance are, for example, 33 rows 12 as shown in the following equation (20). It is stored in the form of a matrix f _t columns.

本実施形態では、ターゲットが指定されなかった評価点における結像性能は、最適化計算では考慮しないこととなっている。従って、解を得てから、再度結像性能を評価する必要がある。

In the present embodiment, the imaging performance at the evaluation point where the target is not specified is not considered in the optimization calculation. Therefore, it is necessary to evaluate the imaging performance again after obtaining the solution.

In the next step 284, after the screen for designating the optimization field range is displayed on the display, the loop from step 286 to step 290 is repeated, and the field range is displayed for a predetermined time from the start of the display of the optimization field range designation screen. Wait for it to be specified. Here, the optimization field range can be specified in scanning exposure devices such as so-called scanning steppers, the imaging performance or the pattern transfer state on the object is not always optimal over the entire field of the projection optical system. and there is no need to reduction, by the size of the stepper is a use also, Relais chicle or pattern area as in the present embodiment (i.e., the whole or part of the pattern region used for the exposure of the wafer) Considering that it is not always necessary to optimize the imaging performance or the transfer state of the pattern on the object in the entire field of view of the projection optical system.

  If the optimization field range is specified within a predetermined time, the process proceeds to step 288, the specified range is stored in a memory such as a RAM, and then the process proceeds to step 294 in FIG. On the other hand, if the optimization field range is not specified, the process proceeds to step 294 without doing anything.

  In step 294, the current imaging performance is calculated based on the above equation (10).

In the next step 296, using the wavefront aberration change table for each adjustment parameter (see Equation (9) above) and the ZS (Zernike Sensitivity) file, that is, the Zernike sensitivity table, the imaging performance change for each adjustment parameter. Create a table. This can be expressed by the following equation (21).

Imaging performance change table = Wavefront aberration change table / ZS file (21)
Since the calculation of the equation (21) is a multiplication of the wavefront aberration change table (matrix with 33 rows and 37 columns) and the ZS file (matrix with 37 rows and 12 columns), the obtained imaging performance change table B1 is, for example, This is a matrix of 33 rows and 12 columns represented by the following equation (22).

かかる結像性能変化表を、１９個の調整パラメータ毎に算出する。この結果、それぞれが３３行１２列のマトリックスから成る１９個の結像性能変化表Ｂ１〜Ｂ１９が得られる。

The imaging performance change table is calculated for each of 19 adjustment parameters. As a result, 19 image formation performance change tables B1 to B19 each having a matrix of 33 rows and 12 columns are obtained.

In the next step 298, the imaging performance f and its target _ft are lined up (one-dimensional). Here, a row of A, these f is a matrix of 33 rows and 12 columns, the f _t, which means that the format conversion in a matrix of 396 rows and 1 column. The f and f _t after being aligned are as shown in the following equations (23) and (24), respectively.

次のステップ３００では、上記ステップ２９６で作成した１９個の調整パラメータ毎の結像性能変化表を２次元化する。ここで、この２次元化とは、それぞれが３３行１２列のマトリックスである１９種類の結像性能変化表を、１つの調整パラメータに対する各評価点の結像性能変化を一列化して、３９６行１９列に形式変換することを意味する。この２次元化後の結像性能変化表は例えば次式（２５）で示されるＢのようになる。

In the next step 300, the imaging performance change table for each of the 19 adjustment parameters created in step 296 is two-dimensionalized. Here, the two-dimensionalization means 19 types of imaging performance change tables each of which is a matrix of 33 rows and 12 columns, and changes the imaging performance change of each evaluation point with respect to one adjustment parameter into a column. This means format conversion to 19 columns. The imaging performance change table after the two-dimensionalization is, for example, B shown by the following equation (25).

上記のようにして、結像性能変化表の２次元化を行った後、ステップ３０２に移行し、前述の制約条件を考慮することなく、調整パラメータの変化量（調整量）を計算する。

After the two-dimensionalization of the imaging performance change table as described above, the process proceeds to step 302, and the change amount (adjustment amount) of the adjustment parameter is calculated without considering the above-described constraint conditions.

Hereinafter, the processing in step 302 will be described in detail. And target f _t of the imaging performance after a row of the foregoing, the imaging performance f after one row of the imaging performance change table B after two-dimensional, between the adjustment amount dx of the adjustment parameters, When weight is not taken into consideration, there is a relationship of the following equation (26).

_{(F t -f) = B ·} dx ...... (26)
Here, dx is a matrix of 19 rows and 1 column represented by the following expression (27) having the adjustment amount of each adjustment parameter as an element. ( _Ft− f) is a 396 × 1 matrix represented by the following equation (28).

上式（２６）を最小自乗法で解くと、次式のようになる。
ｄｘ＝（Ｂ^T・Ｂ）^-1・Ｂ^T・（ｆ_t−ｆ） ……（２９）
ここで、Ｂ^Tは、前述の結像性能変化表Ｂの転置行列であり、（Ｂ^T・Ｂ）^-1は、（Ｂ^T・Ｂ）の逆行列である。

When the above equation (26) is solved by the least square method, the following equation is obtained.
dx = (B ^T · B) ⁻¹ · B ^T · ( _ft −f) (29)
Here, B ^T is a transposed matrix of the imaging performance change table B described above, and (B ^T · B) ⁻¹ is an inverse matrix of (B ^T · B).

  However, when there is no designation of weight (all weights = 1), it is rare, and since there is usually designation of a weight, the merit function Φ which is a weighting function represented by the following equation (30) is minimized. It will be solved by the square method.

ここで、ｆ_tiは、ｆ_tの要素であり、ｆ_iはｆの要素である。上式を変形すると、次のようになる。

Here, f _ti is an element of f _t , and f _i is an element of f. The above equation is transformed as follows.

従って、ｗ_i ^1/2・ｆ_iを新たな結像性能（収差）ｆ_i’とし、ｗ_i ^1/2・ｆ_tiを新たなターゲートｆ_ti’とすると、メリット関数Φは、次のようになる。

Therefore, when w _i ^1/2 · f _i is a new imaging performance (aberration) f _i ′ and w _i ^1/2 · f _ti is a new targe f _ti ′, the merit function Φ is as follows: become.

従って、上記式（３２）を最小自乗法で解いても良い。但し、この場合、結像性能変化表として、次式で示される結像性能変化表を用いる必要がある。

Therefore, the above equation (32) may be solved by the method of least squares. However, in this case, it is necessary to use an imaging performance change table represented by the following equation as the imaging performance change table.

このようにして、ステップ３０２では、制約条件を考慮することなく、最小自乗法により、ｄｘの１９個の要素、すなわち前述の１９個の調整パラメータＰＡＲＡ１〜ＰＡＲＡ１９の調整量を求める。

In this way, in step 302, the 19 elements of dx, that is, the adjustment amounts of the 19 adjustment parameters PARA1 to PARA19 described above are obtained by the least square method without considering the constraint conditions.

  In the next step 303, the obtained adjustment amounts of the 19 adjustment parameters are substituted into the above-described equation (26), for example, and each of the elements of the matrix f, that is, 12 types of aberrations (imaging) at all evaluation points. Performance).

  In the next step 304, it is determined whether or not the 12 types of aberrations at all of the calculated evaluation points are within the range of the individual tolerance values set previously. If this determination is negative, the above-described step is performed. Return to 240. Thereafter, the target and weight are reset by the processing in step 240 and subsequent steps, and the optimization processing is performed.

  On the other hand, if the determination in step 304 is affirmed, the process proceeds to step 306, where it is determined whether or not the adjustment amounts of the 19 adjustment parameters calculated in step 302 violate the previously set constraint conditions. Judgment (this judgment method will be further described later). And when this judgment is affirmed, it transfers to step 308.

  Hereinafter, the processing at the time of violation of the constraint condition including this step 308 will be described.

  The merit function when this constraint condition is violated can be expressed by the following equation (34).

Φ = Φ ₁ + Φ ₂ ...... (34)
In the above equation, Φ ₁ is a normal merit function expressed by Equation (30), and Φ ₂ is a penalty function (a constraint violation amount). When the constraint condition is g _j and the boundary value is b _j , Φ ₂ is a square sum with weight (weight) of the boundary value infringement amount (g _j −b _j ) expressed by the following equation (35). To do.

ここで、Φ₂を境界値侵害量の２乗和にするのは、Φ₂を侵害量の２乗和の形式とすると、最小自乗法の計算で、次式（３６）がｄｘについて解けるからである。

Here, to the [Phi ₂ to the boundary value infringement of square sum, when the sum of squares form of infringement amount [Phi _2, the calculation of the least squares method, from the following equation (36) is solved for dx It is.

すなわち、通常の最小自乗法と同様に、ｄｘが求まる。

That is, dx is obtained in the same manner as in the ordinary least square method.

  Next, specific processing at the time of violation of the constraint conditions will be described.

The constraint condition is physically determined by the movable range and the tilt (θx, θy) limit of each of the three driving axes (such as piezoelectric elements) such as the movable lenses 13 _{1 to} 13 ₅ .

  With zl, z2, and z3 as the position of each axis, the movable range of each axis is expressed by the following equations (37a) to (37c).

z1a≤z1≤z1b (37a)
z2a≤z2≤z2b (37b)
z3a≤z3≤z3b (37c)
In addition, the tilt-specific limit is represented by the following equation (37d) as an example.

(Θx ² + θy ² ) ^1/2 ≦ + 40 ″ (37d)
The reason for 40 ″ is as follows. When 40 ″ is converted to radians,
40 ″ = 40/3600 degrees = π / (90 × 180) radians = 1.93925 × 10 ⁻⁴ radians.

Therefore, for example, when the radius r of the movable lenses 13 _{1 to} 13 ₅ is about 200 mm, the movement amount of each axis is
Axis travel = 1.93925 × 10 ⁻⁴ × 200 mm
= 0.03878mm
= 38.78 μm≈40 μm
It becomes. That is, when the tilt is 40 ″, the periphery moves from the horizontal position by about 40 μm. Since the movement amount of each axis is about 200 μm, the average stroke is 40 μm compared to the axis stroke of 200 μm. Note that the tilt limit is not limited to 40 ″, and may be arbitrarily set according to, for example, the stroke of the drive shaft. In addition to the above-described movable range and tilt limit, the constraint condition may also take into account the shift range of the wavelength of the illumination light EL and the movable range related to the Z direction and tilt of the wafer (Z tilt stage 58).

  In order not to violate the constraint conditions, the above equations (37a) to (37d) need to be satisfied at the same time.

Therefore, first, as described in step 302 above, optimization is performed without considering the constraint condition, and the adjustment amount dx of the adjustment parameter is obtained. This dx can be expressed by a movement vector k0 (Z _i , θx _i , θy _i , i = 1 to 7) as shown in the schematic diagram of FIG. Here, i = 1 to 5 correspond to the movable lenses 13 _{1 to} 13 ₅ , i = 6 corresponds to the wafer (Z tilt stage), and i = 7 corresponds to the wavelength shift of the illumination light. The wavelength of the illumination light does not have three degrees of freedom, but it is assumed that there are three degrees of freedom for convenience.

  Next, it is determined whether or not at least one of the conditions of the above expressions (37a) to (37d) is satisfied (step 306). If this determination is negative, that is, the above expressions (37a) to (37d) are If the conditions are satisfied at the same time, the restriction condition violation process is not necessary, and the restriction condition violation process is terminated (step 306 → 310). On the other hand, when at least one of the conditions of the above formulas (37a) to (37d) is not satisfied, the routine proceeds to step 308.

  In this step 308, as shown in FIG. 12, the obtained movement vector k0 is scaled down to find conditions and points that violate the constraints first. Let that vector be k1.

  Next, assuming that condition as a constraint condition, the constraint condition violation amount is added as an aberration, and optimization calculation is performed again. At that time, the imaging performance change table regarding the constraint violation amount is calculated at the point of k1. In this way, the movement vector k2 in FIG. 12 is obtained.

Here, a constraint violation amount regarded as aberrations, constraint violations amount, for example, z1-z1b, z2-z2b , z3-z3b, (θx 2 + θy 2) is expressed as like ^1/2 -40, This means that the constraint violation amount can be a constraint aberration.

  For example, when z2 violates the constraint condition of z2 ≦ z2b, the constraint condition violation amount (z2−z2b) is regarded as aberration, and normal optimization processing is performed. Accordingly, in this case, a row for the constraint condition is added to the imaging performance change table. Restrictions are also added to the imaging performance (aberration) and its target. At this time, if the weight is set large, z2 is fixed to the boundary value z2b as a result.

  Since the constraint condition is a non-linear function related to z, θx, and θy, different derivatives can be obtained depending on where the imaging performance change table is taken. Therefore, it is necessary to sequentially calculate the adjustment amount (movement amount) and the imaging performance change table.

  Next, as shown in FIG. 12, the vector k2 is scaled to find conditions and points that violate the constraints first. The vector up to that point is k3.

  Thereafter, the above-described constraint conditions are sequentially set (addition of constraint conditions in the order in which the movement vector violates the constraint conditions), and the process of obtaining the movement amount (adjustment amount) by optimizing again until the constraint conditions are no longer violated. repeat.

As a result, k = kl + k3 + k5 + as a final movement vector (38)
Can be requested.

  In this case, for simplicity, k1 may be used as a solution (answer), that is, linear approximation may be performed. Alternatively, when searching for the optimum value strictly within the range of the constraint condition, k in the above equation (38) may be obtained by sequential calculation.

  Next, optimization in consideration of constraint conditions will be further described.

As mentioned above, in general,
_{(F t -f) = B ·} dx ...... (26)
Is established.
By solving this by the method of least squares, the adjustment amount dx of the adjustment parameter can be obtained.

  However, the imaging performance change table can be divided into a normal change table and a constraint condition change table as shown in the following equation (39).

ここで、Ｂ₁は通常の結像性能変化表で、場所に依存しない。一方、Ｂ₂は制約条件の変化表で、場所に依存する。

Here, B ₁ is a normal imaging performance change table and does not depend on the location. On the other hand, B ₂ is a constraint condition change table and depends on the location.

Also, the left side of the equation (26) in response thereto (f _t -f) can also be divided into two as in the following equation (40).

ここで、ｆ_t1は通常の収差のターゲットであり、ｆ₁は現在収差である。また、ｆ_t2は制約条件であり、ｆ₂は現在の制約条件違反量である。

Here, f _t1 is a target for normal aberration, and f ₁ is the current aberration. Further, f _t2 is a constraint condition, and f ₂ is a current constraint condition violation amount.

Since the constraint condition change table B ₂ , the current aberration f ₁ , and the current constraint condition violation amount f ₂ depend on the location, it is necessary to newly calculate for each movement vector.

  After that, if the optimization calculation is performed in the same manner as usual using this change table, the optimization is performed in consideration of the constraints.

  In step 308, after obtaining the adjustment amount considering the constraint conditions as described above, the process returns to step 303.

  On the other hand, when the determination in step 306 is negative, that is, when there is no constraint condition violation and when the constraint condition violation is resolved, the process proceeds to step 310 and the result is displayed on the display. In the present embodiment, as a result display method, the adjustment amount of 19 adjustment parameters (in this case, the amount of change from the position in the reference ID), the value of each adjustment parameter after adjustment, and the imaging performance after optimization ( 12 types of aberration), wavefront aberration correction amount (same value as wavefront aberration correction amount in reference ID), OK button and NG button are displayed.

  Then, looking at the display screen of the result, when the operator points the NG button with a mouse or the like, the process returns to the above-described step 240. Here, the NG button is selected because, for example, the set weight and the target tolerance value are satisfied, but it is desired to further improve the imaging performance at a specific aberration or a specific evaluation point. For example, the operator may want to reset the weight and perform optimization again.

On the other hand, looking at the display screen of the result, when the operator of the OK button pointing with a mouse or the like, the process proceeds to step 314, based on the calculated adjustment amounts, the first main control of the communication server 920 and the exposure apparatus 922 ₁ Each adjustment unit (at least one of the Z position and inclination of the movable lenses 13 _{1 to} 13 ₅ and the wafer W and the wavelength shift amount of the illumination light) is controlled via the apparatus 50.

In this case, as the adjustment amount of the movable lens 13 _i (i = 1 to 5), the displacement amount in the three degrees of freedom direction of Z, θx (rotation around the x axis), and θy (rotation around the y axis) is calculated. If so, these adjustment amounts are converted into drive amounts z1, z2, and z3 for the respective axes as follows.

FIG. 13 shows the arrangement of the drive shafts of the movable lens 13 _i . In order to convert Z, θx, θy into drive amounts z1, z2, z3 of the respective axes (# 1, # 2, # 3) from the geometrical relationship shown in this figure, the following equations (41a) to (41a) to It can be seen that the calculation of (41c) may be performed.

z1 = Zr × tan θx (41a)
z2 = Z + 0.5 × r × tan θx + r × cos 30 ° × tan θy (41b)
z 3 = Z + 0.5 × r × tan θx−r × cos 30 ° × tan θy (41c)
That is, in the second communication server 930, the movable lens _{131-134 5} for example, based on the conversion result to the command value to the effect that the drive to each degree of freedom directions, giving imaging performance correction controller 48. Thereby, the imaging performance correction controller 48 controls the applied voltage to each drive element that drives the movable lenses 13 _{1 to} 13 ₅ in the respective degrees of freedom.

  In the present embodiment, the aforementioned adjustment parameters include the driving amounts Wz, Wθx, Wθy of the wafer W, and the wavelength shift amount Δλ of the illumination light EL, and the adjustment amounts corresponding to these four adjustment parameters are also first described. It has been calculated. The adjustment amounts of these four adjustment parameters are stored in the memory in association with the above-described optimized exposure conditions (including illumination conditions), and from the memory when the pattern is transferred to the wafer under the exposure conditions. It is read and used. That is, the adjustment amounts of the three adjustment parameters relating to the wafer are used in the focus leveling control of the wafer using the focus detection system described above, and the adjustment amount of the adjustment parameter relating to the wavelength of the illumination light is the center wavelength of the illumination light in the light source 16 It will be used for setting. The adjustment amount or drive amount of the movable lens described above is also stored in the memory in association with the optimized exposure conditions described above, and is read from the memory when the pattern is transferred to the wafer under the exposure conditions. The movable lens may be driven.

The control of each adjustment portion of the exposure apparatus 922 ₁ is optimized, formation state on the wafer W of the projected image of the reticle pattern at the time of exposure is to be optimized.

  Thereafter, the processing routine of the first mode (mode 1) is terminated, and the process returns to step 122 of the main routine of FIG.

On the other hand, if the operator selects mode 2 with the mouse or the like in step 110, the determination in step 114 is affirmed and a subroutine for performing mode 2 processing in step 116 (hereinafter referred to as “mode 2 processing routine”). (Also called). Here, mode 2 is a mode in which optimization is performed based on actually measured data of wavefront aberration (or imaging performance) under an arbitrary exposure condition (arbitrary ID). This mode 2 is mainly selected when a new ID is newly added. According to an optimized result by the mode 1 and as described above in a state where each of the control sections of the above is adjusted, while using the exposure apparatus 922 _1, for example, a service engineer or the like, such as during maintenance, the wavefront aberration of the projection optical system When measurement is performed, the processing of mode 2 described below is performed based on the actual measurement data of the wavefront aberration, and as a result, errors such as calculation adjustment amounts in mode 1 can be corrected. .

  When this mode 2 is selected, the premise is that the wavefront aberration of the projection optical system PL is measured with the current ID (optimization target ID) of the target machine. Therefore, here, it is assumed that information indicating that the wavefront aberration has been measured is sent together with the designation of the exposure apparatus (unit) to be optimized and the optimization instruction by the above-described e-mail or the like.

In the processing routine of mode 2 (hereinafter also referred to as “second mode”), first, in step 402 of FIG. 14, information on the exposure condition to be optimized is acquired. Specifically, the first communication server 920 (or target Unit via the first communication server 920 (exposure apparatus 922 ₁₎ of the main control unit 50), the current projection of the target Unit (exposure apparatus 922 ₁₎ N. of the optical system. A. Inquires and acquires setting information such as illumination conditions (illumination NA or illumination σ, aperture stop type, etc.) and target pattern type.

In the next step 406, the first communication server 920 (or target Unit via the first communication server 920 (exposure apparatus 922 ₁₎ of the main control unit 50), a new wave front measurement data (first measurement point to the n coefficients of the terms of the Zernike polynomial in which to expand the wavefront corresponding to the measurement point, for example, the coefficient Z ₃₇₎ and necessary information related to that of the first term of the coefficient Z ₁ ~ paragraph 37, specifically, the wavefront aberration The value of adjustment amount (adjustment parameter) at the time of measurement is acquired by communication. The value of this adjustment amount, that is, the position information in the three-degree-of-freedom direction of the movable lenses 13 _{1 to} 13 ₅ , etc., usually coincides with the current value, that is, the value under the exposure condition to be optimized.

  In the next step 408, as in the above-described step 208, the model name of the target machine, the exposure wavelength, and the maximum N.D. A. Get device information.

  In the next step 410, the ZS file corresponding to the optimized exposure condition is searched from the second database, as in step 210 described above.

  Then, in steps 414, 416, and 418, the same processing (including determination) as in steps 214, 216, and 218 described above is performed. As a result, if the ZS file corresponding to the optimized exposure condition in the second database is in the second database, it is read into the memory, and if not, the ZS file is created by the interpolation method described above. The

  Next, in steps 420 to 438 in FIG. 15, processing (including determination) similar to that in steps 220 to 238 described above is performed. Thereby, the allowable value of the imaging performance and the restriction condition of the adjustment amount are set.

  Next, in steps 440 to 462 in FIG. 16, the same processing (including determination) as in steps 240 to 262 described above is performed. As a result, 12 types of aberration weights are set at 33 evaluation points (measurement points) in the field of the projection optical system in the same manner as described above. However, in this second mode process, when automatic designation is selected in step 446, the process proceeds to step 450, and the current imaging performance is calculated based on the following equation (42).

f = Wa ′ · ZS (42)
Here, f is the imaging performance represented by the above equation (11), and ZS is the data of the ZS file represented by the above equation (13) acquired in step 416 or 418. Wa ′ is wavefront aberration data (actual measurement data) represented by the following equation (43) acquired in step 406. That is, the second mode is different from the first mode (mode 1) in that actually measured data is used for calculating the imaging performance.

上式（４３）において、Ｚ_i,j’は、ｉ番目の計測点における波面収差のツェルニケ多項式の第ｊ項（ｊ＝１〜３７）の係数を示す。

In the above equation (43), Z _{i, j} ′ represents the coefficient of the j-th term (j = 1 to 37) of the Zernike polynomial of wavefront aberration at the i-th measurement point.

  Next, in steps 464 to 490 in FIG. 17, the same processing (including determination) as the above-described steps 264 to 290 is performed. As a result, when the target values (targets) of 12 types of aberrations at 33 evaluation points in the field of the projection optical system are set and the optimization field range is specified, the setting (stored in the memory) is performed. ) Is performed. However, in this mode 2 processing, when setting assistance is designated (selected) in step 470, the aberration decomposition method is executed in step 476. At this time, the result calculated by the above equation (42) is used. An image performance f is used.

  Next, in step 494 of FIG. 18, the current imaging performance is calculated based on the above-described equation (42).

  In the next step 496, an imaging performance change table for each adjustment parameter is created in the same manner as in step 296 described above.

In the next step 498, the imaging performance f calculated in step 494 and its target ft are _aligned (one-dimensional).

  Next, in step 500, the imaging performance change table for each of the 19 adjustment parameters is two-dimensionalized in the same manner as in step 300 described above, and then the process proceeds to step 502 and the constraint conditions are set in the same manner as in step 302 described above. The change amount (adjustment amount) of the adjustment parameter is calculated without consideration.

  In the next step 503, the obtained adjustment amounts of the 19 adjustment parameters are substituted into the above-described equation (26), for example, and the 12 types of aberrations (imaging) at each element of the matrix f, that is, at all evaluation points. Performance).

  In the next step 504, it is determined whether or not the 12 types of aberrations at all of the calculated evaluation points are within the range of the individual allowable values set previously. If this determination is negative, the above-described step is performed. Return to 440. Thereafter, the target and weight are reset by the processing in step 440 and subsequent steps, and optimization processing is performed.

  On the other hand, if the determination in step 504 is affirmed, the process proceeds to step 506, in which whether or not the adjustment amount of the 19 adjustment parameters calculated in step 502 violates the previously set constraint condition. Judgment is made in the same manner as described above. If this determination is affirmed, the process proceeds to step 508, and in the same manner as in step 308 described above, the constraint conditions are sequentially set and optimized again to obtain the adjustment amount in the same manner as in step 308 described above. After that, the process returns to step 503.

  On the other hand, if the determination in step 506 is negative, that is, if there is no constraint condition violation or if the constraint condition violation is resolved, the process proceeds to step 510 and the result is displayed on the display. In the present embodiment, as a result display method, the adjustment amount of 19 adjustment parameters (in this case, the amount of change from the initial value), the value of each adjustment parameter after adjustment, and the imaging performance after optimization (12 types) ), The wavefront aberration correction amount, and an OK button and an NG button.

  Then, looking at the display screen of this result, when the operator points the NG button with a mouse or the like, the process returns to step 440.

On the other hand, looking at the display screen of the result, when the operator of the OK button pointing with a mouse or the like, the process proceeds to step 514, based on the calculated adjustment amounts, the first main control of the communication server 920 and the exposure apparatus 922 ₁ Each adjustment unit (at least one of the Z position and inclination of the movable lenses 13 _{1 to} 13 ₅ and the wafer W and the wavelength shift amount of the illumination light) is controlled through the apparatus 50 in the same manner as described above. As a result, the exposure apparatus 922 ₁ is optimized, and the formation state of the projected image of the reticle pattern on the wafer W at the time of exposure is optimized.

  Thereafter, the processing routine of the second mode (mode 2) is terminated, and the process returns to step 122 of the main routine of FIG.

Furthermore, if the operator selects mode 3 with the mouse or the like in step 110, the determination in step 114 is denied, and a subroutine for performing mode 3 processing in step 120 (hereinafter referred to as “mode 3 processing routine”). To call). Here, mode 3 refers to imaging performance under an arbitrary exposure condition (arbitrary ID) in a state where the wavefront aberration in a reference state is known and the value of the adjustment parameter at that time is fixed. In this case, the above-described 12 types of aberration) are obtained. This mode 3 is suitable not only for device manufacturers but also for improving imaging performance and bringing it closer to a desired target, for example, when adjusting the optical characteristics of the projection optical system in the manufacturing stage at an exposure apparatus manufacturer. Can be used.

In the processing routine of this mode 3 (hereinafter also referred to as “third mode”), first, in step 602 of FIG. 19, the target machine (exposure device 922 ₁₎ via the first communication server 920 (or the first communication server 920). ), The value of the adjustment amount (adjustment parameter) in the current state, the single wavefront aberration, and the wavefront aberration correction amount for the single wavefront aberration are acquired. This acquired information becomes information in the reference state of this mode 3.

In the next step 604, the model name, exposure wavelength, and maximum N. of the projection optical system from the first communication server 920 (or the main control device 50 of the target machine (exposure device 922 ₁ ) via the first communication server 920). A. Get device information.

  In the next step 606, after the target pattern information input screen is displayed on the display, the process proceeds to step 608 to wait for the target pattern information to be input.

  Then, information on the target pattern (type of blank pattern or remaining pattern, type of dense pattern or isolated pattern, pitch, line width, isolated line in case of dense lines (line and space, etc.) via the keyboard or the like by the operator Line width in case of contact, length in width in case of contact hole, width, distance between hole patterns (pitch, etc.), phase shift pattern (including halftone type) or phase shift reticle and its type (for example, spatial frequency) If a modulation type, halftone type, etc.) are input, the process proceeds to step 610 and the input pattern information is stored in a memory such as a RAM.

  In the next step 612, after the illumination condition input screen is displayed, the process proceeds to step 614 to wait for the input of the illumination condition information. Then, information on illumination conditions, for example, illumination N.D. A. Alternatively, when information such as illumination σ, annular ratio, aperture shape of illumination system aperture stop (secondary light source shape) is input, the input illumination condition is stored in a memory such as a RAM in step 615.

  In the next step 616, after the NA input screen of the projection optical system is displayed on the display, the process proceeds to the next step 617 and the N.A. A. Wait for input. When the operator inputs N.A. via the keyboard or the like, the process proceeds to step 618 (FIG. 20), and the input N.A. is stored in a memory such as a RAM.

  In the next step 619, a screen for specifying a target aberration (hereinafter referred to as “target aberration” as appropriate) that is an object for evaluating the imaging performance is displayed on the display, and then the process proceeds to step 620 to specify the target aberration. It is determined whether or not. Here, on the designation screen for the target aberration, a designation completion button is also displayed.

  When one of the above-mentioned 12 types of aberrations is designated as the target aberration via the keyboard or the like by the operator, the designated target aberration is stored in a memory such as a RAM as an evaluation target, and the process proceeds to step 624. It is determined whether or not designation completion is instructed. If this determination is denied, the process returns to step 620. On the other hand, if the determination in step 620 is negative, the process proceeds to step 624.

  That is, in this embodiment, the loop of step 620 → 622 → 624 or the loop of step 620 → 624 is repeated to wait for the completion of the designation of the target aberration. When the operator points to the designation completion button via the mouse or the like, the process proceeds to step 626. Here, the method of specifying the target aberration (evaluation item) is not limited to the above-described specification of the target aberration by direct input. For example, for each different evaluation item corresponding to the same illumination condition and NA of the projection optical system. It is also possible to designate the target aberration (evaluation item) by selecting the ZS file. At this time, a plurality of target aberrations (evaluation items) may be designated.

  In step 626, a ZS file corresponding to the evaluation condition is searched from the second database. Here, the evaluation condition is an evaluation under the conditions to be evaluated, that is, under the exposure conditions (hereinafter referred to as “target exposure conditions” as appropriate) determined by the information input in steps 610, 615, and 618, respectively. It means the condition for evaluating the imaging performance of the item (here, the target aberration specified in step 620 and stored in the memory in step 622).

  In the next step 628, it is determined whether or not a ZS file corresponding to the evaluation condition has been found. If found, the ZS file is read into a memory such as a RAM. On the other hand, if the determination in step 628 is negative, that is, if the ZS file corresponding to the evaluation condition does not exist in the second database, the process proceeds to step 632 to change the ZS database in the second database. A ZS file corresponding to the evaluation condition is created using, for example, the interpolation method described above.

  In the next step 634, the imaging performance of the evaluation item (here, the target aberration specified in step 620 and stored in the memory in step 622) under the target exposure condition is calculated as follows.

  That is, substituting the wavefront aberration data obtained from the information acquired in step 602 and the ZS file data read in step 630 or created in step 632 into the above-described equation (10). Thus, the imaging performance at each evaluation point in the field of view is calculated.

  In the next step 636, the calculated imaging performance information is displayed on the display. At this time, an OK button and a redo button are displayed together with information on the imaging performance on the display.

  By displaying the imaging performance described above, the operator can recognize the imaging performance that is an evaluation item under the target exposure condition specified by the operator.

  For example, when the imaging performance under the target exposure condition should be sufficiently satisfied, the operator who views the display points the OK button using a mouse or the like. As a result, the processing in the third mode ends, and the process returns to step 122 of the main routine of FIG.

  On the other hand, if the image formation performance under the target exposure condition is not sufficiently satisfied by looking at the display content, the operator can set the redo button to a mouse or the like to know the image formation performance under another target exposure condition. Use to point. As a result, the process returns to step 606, the pattern information input screen is displayed again, and the processing (including judgment) after step 608 is repeated.

  Here, in the third mode, the operator can easily determine the best exposure condition by repeatedly pressing the redo button and calculating and displaying the imaging performance by setting various exposure conditions as the target exposure conditions. That is, for example, the ZS file creation (or selection) and imaging performance described above are repeatedly performed by repeatedly pressing the redo button while gradually changing the pattern information while the designation information other than the pattern information input in step 608 is fixed. By repeatedly calculating (target aberration) and sequentially checking the display of the calculation results in step 636, by finding pattern information that minimizes (or optimizes) the imaging performance (target aberration), the best exposure condition is obtained. As a result, an optimum pattern can be determined.

  Similarly, while the remaining designation information is fixed, only the specific condition is gradually changed, and the redo button is repeatedly pressed to create (or select) the above ZS file and calculate the imaging performance (target aberration). Are repeatedly performed, and the display of the calculation result in step 636 is sequentially confirmed to find the specific condition that minimizes (or optimizes) the imaging performance, thereby determining the optimal specific condition as the best exposure condition. be able to.

Returning to the description of FIG. 5, in step 122, a screen for selecting whether to end or continue is displayed on the display. When continue is selected in step 124, the process returns to step 102. On the other hand, when the end is selected, a series of processing of this routine is ended.

  As described above, in the first mode of processing, there may be a case where the wavefront aberration correction amount in the reference ID is unknown. In this case, the wavefront aberration correction amount can be estimated from this imaging performance. This will be described below.

Here, the deviation of the wavefront aberration of a single wavefront aberration and on body estimates the correction amount of the wavefront aberration on the assumption that correspond to the deviation [Delta] x 'of the adjustment amount of the adjusting parameters such as the movable lens _{131-134 5} described above.

When the single wavefront aberration and the on-body wavefront aberration are the same, the adjustment amount is Δx, the adjustment amount is Δx ′, the ZS file is ZS, and the theoretical imaging performance with reference ID (on-body wavefront) Theoretical imaging performance when there is no aberration deviation) is K ₀ , the actual imaging performance with the reference ID (same adjustment parameter value) is K ₁ , the wavefront aberration change table is H, and the imaging performance change table is When H ′, the single wavefront aberration is Wp, and the wavefront aberration correction amount is ΔWp, the following two expressions (44) and (45) are established.

K ₀ = ZS · (Wp + H · Δx) (44)
K ₁ = ZS · (Wp + H · (Δx + Δx ′)) (45)
Than this,
K ₁ −K ₀ = ZS · H · Δx ′ = H ′ · Δx ′ (46)
From this, when the above equation (46) is solved by the least square method,
The correction amount Δx ′ of the adjustment amount can be expressed as the following equation (47).
^{Δx '= (H' T ·} H ') -1 · H' T · (K 1 -K 0) ...... (47)
Further, the wavefront aberration correction amount ΔWp can be expressed by the following equation (48).
ΔWp = H · Δx ′ (48)
Each reference ID has this wavefront aberration correction amount ΔWp.
The actual on-body wavefront aberration is expressed by the following equation (49).
Actual on-body wavefront aberration = Wp + H · Δx + ΔWp (49)

By the way, in the exposure apparatuses 922 _{1 to} 922 _{3 of} the present embodiment, when manufacturing a semiconductor device, a reticle R for device manufacture is loaded on the reticle stage RST, and then reticle alignment, so-called baseline measurement, and EGA (enhanced) are performed.・ Preparation work such as wafer alignment such as global alignment is performed.

  Note that the above-described preparation operations such as reticle alignment and baseline measurement are disclosed in detail in, for example, Japanese Patent Laid-Open No. 4-324923 and US Pat. No. 5,243,195 corresponding thereto. The subsequent EGA is disclosed in detail in JP-A-61-44429 and US Pat. No. 4,780,617 corresponding thereto.

  After that, step-and-repeat exposure is performed based on the wafer alignment result. It should be noted that the operation at the time of exposure is not different from that of a normal stepper, and detailed description thereof is omitted.

Next, a method of manufacturing the projection optical system PL performed when manufacturing the exposure apparatus 922 (922 _{1 to} 922 ₃ ) will be described with reference to the flowchart of FIG. 21 showing the manufacturing process of the projection optical system PL.

  Here, as a premise, it is assumed that a computer system having the same configuration as in FIG. 1 is built in the factory of an exposure apparatus manufacturer (maker B). In the following, the same reference numerals as those of the computer system on the device manufacturer A side described above are used as the reference numerals of the respective components. Also, here, for convenience of explanation, it is assumed that the first communication server 920 is installed at the manufacturing site of the projection optical system PL.

[Step 1]
In step 1, first, each lens element as each optical member constituting the projection optical system PL according to a design value based on predetermined design lens data, a lens holder that holds each lens, and an optical unit that includes the lens element and the lens holder Manufactures a lens barrel that houses That is, each lens element is processed to have a radius of curvature and an axial thickness according to a predetermined design value from a predetermined optical material using a known lens processing machine, and a lens holder and lens element for holding each lens The lens barrel that houses the optical unit including the lens holder is processed into a shape having predetermined dimensions from a predetermined holding material (stainless steel, brass, ceramic, etc.) using a known metal processing machine or the like.

[Step 2]
In step 2, the surface shape of the lens surface of each lens element constituting the projection optical system PL manufactured in step 1 is measured using, for example, a Fizeau interferometer. As this Fizeau interferometer, a light source using a He—Ne gas laser that emits light having a wavelength of 633 nm, an Ar laser that emits light having a wavelength of 363 nm, an Ar laser that is harmonicized to a wavelength of 248 nm, or the like is used. According to this Fizeau interferometer, an interference fringe due to interference of reflected light from a reference surface formed on the surface of a condensing lens arranged on an optical path and a lens element surface which is a test surface is used as an imaging device such as a CCD. The shape of the surface to be measured can be obtained accurately by measuring with It is known that the shape of the surface (lens surface) of an optical element such as a lens is obtained using a Fizeau interferometer. This is, for example, disclosed in Japanese Patent Laid-Open Nos. 62-126305 and 6-6-1. No. 185997 and the like.

  Measurement of the surface shape of the optical element using the Fizeau interferometer described above is performed on all lens surfaces of each lens element constituting the projection optical system PL. Then, the operator inputs each measurement result to the first communication server 920 via an input device (not shown) such as a console. The input information is transmitted from the first communication server 920 to the second communication server 930 and stored in a memory such as a RAM provided in the second communication server 930 or a storage device such as a hard disk.

[Step 3]
After the measurement of the surface shapes of all the lens surfaces of each lens element constituting the projection optical system PL in step 2, the optical unit processed and manufactured according to the design value, that is, an optical element such as a lens and the optical element A plurality of optical units each composed of a lens holder for holding the lens is assembled. Of the optical unit, a plurality, for example five, has a movable lens _{131-134 5} described above, respectively, the optical unit having a movable lens _{131-134 5,} as described above, the lens A double-structured lens holder is used as the holder. That is, these double-structured lens holders each have an inner lens holder that holds the movable lenses 13 _{1 to} 13 ₅ and an outer lens holder that holds the inner lens holder. The positional relationship with the holder is adjustable through a mechanical adjustment mechanism. The double lens holder is provided with the drive elements described above at predetermined positions.

  Then, the plurality of optical units assembled as described above are sequentially assembled through the upper opening of the lens barrel so as to be dropped into the lens barrel with a spacer interposed therebetween. Then, the optical unit first dropped into the lens barrel is supported via a spacer by a protrusion formed at the lower end of the lens barrel, and all the optical units are accommodated in the lens barrel. Is completed. In parallel with this assembly process, information on the distance between the optical surfaces (lens surfaces) of each lens element using a tool (micrometer, etc.) while taking into account the thickness of the spacer housed in the lens barrel together with the optical unit Measure. Then, while alternately performing the assembly operation and the measurement operation of the projection optical system, the distance between the optical surfaces (lens surfaces) of the final lens elements of the projection optical system PL at the stage where the assembly process of step 3 is completed is determined. Ask.

In addition, the movable lenses 13 _{1 to} 13 ₅ described above are fixed at a neutral position in each process of the manufacturing stage including this assembly process. Although not described, the pupil aperture stop 15 is also incorporated in this assembly process.

  The operator communicates the measurement result regarding the distance between the optical surfaces (lens surfaces) of the lens elements of the projection optical system PL during the assembly process or at the completion of the assembly via an input device such as a console (not shown). Input to server 920. The input information is transmitted from the first communication server 920 to the second communication server 930 and stored in a memory such as a RAM provided in the second communication server 930 or a storage device such as a hard disk. In the above assembly process, the optical unit may be adjusted as necessary.

  At this time, for example, the relative distance in the optical axis direction between the optical elements is changed or the optical elements are inclined with respect to the optical axis via a mechanical adjustment mechanism. Further, the lens barrel is configured such that the tip of a screw (screw) screwed through a female screw portion that penetrates the side surface of the lens barrel comes into contact with the lens holder, and the screw is screwed through a tool such as a screw driver. By moving the lens holder, the lens holder may be shifted in a direction orthogonal to the optical axis to adjust the eccentricity. Note that an adjustment mechanism for moving the lens holder with five or more degrees of freedom in order to perform optical adjustment of the projection optical system assembled as described above is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-162549.

[Step 4]
Next, in step 4, the wavefront aberration of the projection optical system PL assembled in step 3 is measured.

  Specifically, the projection optical system PL is attached to the body of a large wavefront measuring apparatus (not shown) (for example, the PMI described above), and wavefront aberration is measured. The principle of wavefront measurement by this wavefront measuring apparatus is not different from that of the wavefront aberration measuring instrument 80 described above, and detailed description thereof is omitted.

As a result of the measurement of the wavefront aberration, the coefficient Z _i (i = 1, 2,..., 81) of each term of the Zernike polynomial (Fringe-Zernike polynomial) obtained by developing the wavefront of the projection optical system is obtained by the wavefront measuring apparatus. can get. Therefore, by connecting the wavefront measuring device to the second communication server 930, the coefficients Z _i of the terms of the Zernike polynomial are automatically stored in a memory such as a RAM (or a storage device such as a hard disk) of the second communication server 930. Is captured. In the above description, the wavefront measuring apparatus uses up to the 81st term of the Zernike polynomial, but this is done in order to calculate higher-order components of each aberration of the projection optical system PL. It is. However, it is possible to calculate up to the 37th term as in the case of the wavefront aberration measuring instrument described above, or to calculate more than 82 terms.

[Step 5]
In step 5, the projection optical system PL is adjusted so that the wavefront aberration measured in step 4 is optimum.

  First, prior to the adjustment of the projection optical system PL, the second communication server 930 obtains each piece of information stored in the memory, that is, information relating to the surface shape of each optical element obtained in the above step 2 and the above step 3. In the manufacturing process of the projection optical system PL actually assembled by correcting the optical basic data stored in advance in the memory based on the information about the distance between the optical surfaces of each optical element obtained in the assembling process. Reproduce the optical data. This optical data is used to calculate the adjustment amount of each optical element.

That is, in the hard disk of the second communication server 930, for all of the lens elements constituting the projection optical system PL, the coefficient Z _i of the terms of directions of six degrees of freedom each unit driving amount and Zernike polynomials of each lens element The basic database for adjustment, in which the relationship with the amount of change is calculated based on the design value of the projection optical system, that is, the so-called wavefront aberration change table is expanded to include not only movable lenses but also non-movable lens elements, Stored in advance. Therefore, the second communication server 930 modifies the basic database for adjustment by a predetermined calculation based on the optical data in the manufacturing process of the projection optical system PL described above.

  Then, in the second communication server 930, using the corrected database and the wavefront aberration measurement result described above, a predetermined calculation is performed, and the adjustment amount (including zero) of each lens element in each of the six degrees of freedom direction is calculated. Information is calculated, and information on the adjustment amount is displayed on the display. At the same time, the second communication server 930 transmits the adjustment amount information to the first communication server 920. In the first communication server 920, the adjustment amount is displayed on the information display.

  According to this display, each lens element is adjusted by an engineer (operator). Thereby, the projection optical system PL in which the wavefront aberration is optimized is manufactured.

  In order to easily rework the optical elements of the projection optical system PL, when wavefront aberration is measured using the above-described wavefront measuring apparatus, the presence or absence of optical elements that require reworking based on the measurement results, The position or the like may be specified, and reprocessing of the optical element and readjustment of other optical elements may be performed in parallel.

  Next, a method for manufacturing the exposure apparatus 922 will be described.

  In manufacturing the exposure apparatus 922, first, the illumination optical system 12 including a plurality of lens elements, optical elements such as mirrors is assembled as a single unit, and the projection optical system PL is assembled as a single unit as described above. In addition, a reticle stage system, a wafer stage system, and the like made up of a large number of mechanical parts are each assembled as a unit. Then, optical adjustment, mechanical adjustment, electrical adjustment, and the like are performed so that each unit exhibits desired performance as a single unit. In this adjustment, the projection optical system PL is adjusted by the method described above.

  Next, the illumination optical system 12 and the projection optical system PL are assembled in the exposure apparatus main body, and a reticle stage system, a wafer stage system, etc. are attached to the exposure apparatus main body to connect wiring and piping.

  Next, the illumination optical system 12 and the projection optical system PL are further optically adjusted. This is because the imaging performance of these optical systems, particularly the projection optical system PL, slightly changes before and after assembly to the exposure apparatus main body. In the present embodiment, when the projection optical system PL is optically adjusted after being incorporated into the exposure apparatus body, the wavefront aberration measuring instrument 80 described above is attached to the Z tilt stage 58, and the wavefront aberration is measured in the same manner as described above. The wavefront information at each measurement point obtained as a measurement result of the wavefront aberration is sent online from the main controller 50 of the exposure apparatus being manufactured to the second communication server 930 via the first communication server 920. Then, the second communication server 930 calculates the adjustment amount in each of the six degrees of freedom direction of each lens element in the same manner as the adjustment at the time of manufacturing the projection optical system PL alone, and the calculation result 1 Displayed on the display of the exposure apparatus via the communication server 920.

  And according to this display, each lens element is adjusted by the engineer (operator). Thereby, the projection optical system PL that reliably satisfies the determined specifications is manufactured.

  The final adjustment in the manufacturing stage can be performed by automatic adjustment of the projection optical system PL via the imaging performance correction controller 48 by the main controller 50 based on the instruction from the second communication server 930 described above. is there. However, at the stage where the manufacture of the exposure apparatus is completed, it is desirable to keep each movable lens in a neutral position in order to ensure a sufficient driving stroke of the driving element after delivery to the semiconductor manufacturing factory. Thus, since it can be determined that uncorrected aberrations, mainly higher-order aberrations, are difficult to adjust automatically, as described above, it is desirable to readjust the assembly of the lens and the like.

  In addition, when a desired performance cannot be obtained by the above readjustment, it is necessary to rework or replace some lenses. In order to easily rework the optical elements of the projection optical system PL, the above-mentioned wavefront aberration is measured using a dedicated wavefront measurement device or the like before the projection optical system PL is incorporated into the exposure apparatus body. The presence / absence or position of an optical element that requires reworking is specified based on the above, and reworking of the optical element and readjustment of another optical element may be performed in parallel.

  Further, the replacement or the like may be performed in units of optical elements of the projection optical system PL, or in the projection optical system having a plurality of lens barrels, the replacement may be performed in units of the lens barrels. Furthermore, in the reworking of the optical element, the surface may be processed into an aspherical surface as necessary. Further, in adjusting the projection optical system PL, it is only necessary to change the position of the optical element (including the interval with other optical elements), the inclination, etc. Especially when the optical element is a lens element, the eccentricity is changed. Or may be rotated about the optical axis AX. Further, in order to correct the aberration of the projection optical system PL, particularly the non-rotationally symmetric component, for example, the wavefront aberration is measured in a state in which a plane parallel plate is incorporated in the projection optical system PL, and the projection optical system PL is based on the measurement result. It is also possible to process the surface of the plane-parallel plate taken out from the above and reattach the processed plane-parallel plate (aberration correction plate) to the projection optical system PL. Thereby, the projection optical system PL can be easily adjusted, or the adjustment can be performed with higher accuracy. The wavefront aberration may be measured with the aberration correction plate attached to the projection optical system PL, and the aberration correction plate may be reworked or replaced in accordance with the measurement result.

  Thereafter, comprehensive adjustment (electric adjustment, operation check, etc.) is further performed. As a result, the exposure apparatus 922 of the present embodiment that can accurately transfer the pattern of the reticle R onto the wafer W using the projection optical system PL whose optical characteristics are adjusted with high accuracy can be manufactured. . The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

As is clear from the above description, in the present embodiment, the movable lenses 13 _{1 to} 13 ₅ , the Z tilt stage 58 and the light source 16 constitute an adjustment unit, and the movable lenses 13 _{1 to} 13 ₅ and the Z tilt stage 58 are The position in the Z, θx, and θy directions (or the amount of change) and the shift amount of the wavelength of illumination light from the light source 16 are adjustment amounts. The adjustment unit, the driving element for driving the movable lens and the imaging performance correction controller 48, the wafer stage driving unit 56 for driving the Z tilt stage 58, the imaging performance correction controller 48, and the wafer stage driving unit 56. The main controller 50 that controls the light source 16 constitutes an adjusting device. However, the configuration of the adjustment device is not limited to this, and for example, only the movable lenses 13 _{1 to} 13 ₅ may be included as the adjustment unit. This is because even in such a case, the imaging performance (various aberrations) of the projection optical system can be adjusted.

  Further, in the description so far, the measurement of the wavefront aberration performed when the projection optical system PL is adjusted is based on the aerial image formed through the pinhole and the projection optical system PL using the wavefront aberration measuring instrument 80. However, the present invention is not limited to this. For example, a measurement mask having a special structure disclosed in US Pat. No. 5,978,085 is used, and each of a plurality of measurement patterns on the mask is used. Bake on the object through the pinhole and projection optical system provided individually one after another, and print the reference pattern on the mask onto the object through the projection optical system without going through the condenser lens and pinhole, The registration image of each of the plurality of measurement patterns obtained as a result of each printing is measured with respect to the registration image of the reference pattern, and a predetermined calculation is performed. Aberration may be calculated a.

Further, the wavefront aberration may be measured using a PDI (Point Deflection Interferometer) disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-97617. Further, for example, the phase recovery method disclosed in Japanese Patent Laid-Open No. 10-284368, US Pat. No. 4,309,602 and the like, and the halftone phase shift disclosed in, for example, Japanese Patent Laid-Open No. 2000-146757, etc. A technique using a mask can also be used. Further, for example, JP-A-10-170399, Jena Review 1991/1, pp8-12 "Wavefront analysis of
photolithographic lenses "Wolfgang Freitaget al., Applied Optics Vol. 31,
No.13, May 1, 1992, pp2284-2290. "Aberration
analysis in aerial images formed by lithographic lenses ", Wolfgang Freitag
As disclosed in et al. and Japanese Patent Application Laid-Open No. 2002-22609, a method using a light beam that passes through a part of the pupil of the projection optical system can also be used.

  As described above in detail, according to the computer system 10 according to the present embodiment, when the above-described first mode is selected, the second communication server 930 is under the exposure condition (reference ID) serving as a reference. Based on the adjustment information of the adjustment device and information on the imaging performance of the projection optical system, for example, wavefront aberration, an optimal adjustment amount of the adjustment device under the target exposure condition is calculated. Here, the relationship between the adjustment information of the adjustment device under the reference exposure conditions and the imaging performance of the projection optical system, for example, the wavefront aberration is known, and when the adjustment is performed, the projection optical system The imaging performance should be accurate. Accordingly, the optimum adjustment amount under the target exposure condition calculated based on the adjustment information of the adjustment device under the reference exposure condition and the wavefront aberration of the projection optical system is high in accuracy. Further, the second communication server 930 adjusts the adjustment device described above via the first communication server 920 based on the calculated adjustment amount. Therefore, according to the computer system 10 of the present embodiment, it is possible to quickly optimize the formation state of the projection image on the wafer W by the projection optical system PL of the reticle pattern under an arbitrary target exposure condition. .

  In the present embodiment, the second communication server 930 adjusts the adjustment device based on the calculation result of the optimal adjustment amount. However, the second communication server 930 does not necessarily perform the adjustment. That is, the second communication server 930 may only calculate the adjustment amount described above. Even in such a case, the information on the calculated adjustment amount is transmitted to the first communication server 920, the exposure apparatus 922, or an operator of those apparatuses, for example, by e-mail, etc. Similar to the above-described embodiment, the first communication server 920 and the exposure apparatus 922 can adjust the adjustment apparatus by themselves or according to an operator's instruction. Even in such a case, similarly to the above-described embodiment, the formation state of the projection image on the wafer W by the projection optical system PL of the reticle pattern under an arbitrary target exposure condition can be quickly optimized. .

  In this case, the information relating to the imaging performance described above includes various information as long as it is information that serves as a basis for calculating the optimum adjustment amount of the adjustment device under the target exposure conditions together with the adjustment information of the adjustment device. be able to. In other words, the information on the imaging performance may include information on the wavefront aberration of the projection optical system after adjustment under the exposure conditions used as a reference as in the above-described embodiment, but the information on the imaging performance may be included in the projection performance. Information on the single wavefront aberration of the optical system and the imaging performance of the projection optical system under the reference exposure conditions may be included. In the latter case, the information on the wavefront aberration of the projection optical system after adjustment under the exposure conditions serving as a reference may be calculated from the imaging performance by the above-described wavefront aberration estimation method.

  Further, according to the computer system 10 according to the present embodiment, when the second mode described above is selected, the second communication server 930 can adjust the adjustment information of the adjustment device and the projection optical system under a predetermined target exposure condition. An optimum adjustment amount of the adjustment device under the target exposure condition is calculated based on image formation performance, for example, measured data of wavefront aberration. In other words, based on the actual measurement data of the wavefront aberration of the projection optical system measured under the target exposure condition, the optimal adjustment amount of the adjustment device under the target exposure condition is calculated, so that the accurate adjustment amount can be calculated. It becomes.

  Further, the second communication server 930 adjusts the adjustment device described above via the first communication server 920 based on the adjustment amount calculated in the second mode. Therefore, according to the computer system 10 of the present embodiment, it is possible to quickly optimize the formation state of the projection image on the wafer W by the projection optical system PL of the reticle pattern under an arbitrary target exposure condition. . In this case, since the calculated adjustment amount is based on the actual measurement value, the accuracy is equal to or higher than that in the first mode.

  In this case, as the actual measurement data, any data can be used as long as it is a basis for calculating the optimum adjustment amount of the adjustment device under the target exposure condition together with the adjustment information of the adjustment device. For example, as in the present embodiment, the actual measurement data may include actual measurement data of wavefront aberration under the target exposure condition. However, the measurement data is not limited to this, and the actual measurement data may have any imaging performance under the target exposure condition. Actual measurement data may be included. Even in such a case, the wavefront aberration can be obtained by a simple calculation by using the actual measurement data of the imaging performance and the Zernike sensitivity table (ZS file) described above.

  In the present embodiment, the second communication server 930 creates a Zernike sensitivity table under the target exposure conditions by interpolation calculation based on the Zernike sensitivity tables under the exposure conditions that serve as a plurality of references. Therefore, for example, even if the Zernike sensitivity table under the target exposure condition is not prepared in advance, the target exposure condition is determined by interpolation calculation using, for example, interpolation using the Zernike sensitivity table under the plurality of reference exposure conditions. Zernike sensitivity table can be quickly obtained.

  Further, according to the computer system 10 according to the present embodiment, the wavefront of the projection optical system PL is self-measured by the wavefront aberration measuring instrument 80 provided in the exposure apparatus 922. The first communication server 920 transmits the measurement result of the wavefront of the projection optical system PL measured by the wavefront aberration measuring instrument 80 to the second communication server 930 via the communication path. The second communication server 930 controls the adjustment device described above using the wavefront measurement result. Therefore, the imaging performance of the projection optical system PL is accurately adjusted using information on the wavefront on the pupil plane of the projection optical system, that is, comprehensive information passing through the pupil plane. As a result, adjustment is made so that the image formation state of the pattern by the projection optical system is optimized. In this case, the second communication server 930 can be disposed at a position away from the exposure apparatus 922 and the first communication server 920 connected thereto, and in such a case, the image of the projection optical system PL is remotely controlled. It is possible to adjust the performance, and consequently the image formation state of the pattern by the projection optical system PL with high accuracy.

  Further, when an in-house LAN system as shown in FIG. 1 is built in an exposure apparatus manufacturer, for example, on the clean room side of the research and development department, for example, a place where the exposure apparatus is assembled and adjusted (hereinafter referred to as “site”). The first communication server 920 is installed, and the second communication server 930 is installed in a laboratory away from the site. Then, the technician on the site side measures the wavefront aberration described above and the exposure condition information (including pattern information) of the exposure apparatus at the experimental stage via the first communication server 920 in the second communication on the laboratory side. Send to server 930. Then, a laboratory engineer uses the second communication server 930 in which a software program designed by himself / herself is installed in advance, and based on the sent information, the imaging performance of the projection optical system PL of the exposure apparatus 922 Is automatically corrected from a remote location and the measurement results of the wavefront aberration of the projection optical system after the adjustment of the imaging performance is received, so that the effect of the adjustment of the imaging performance can be confirmed. It can also be used for the development stage.

  Note that the processing algorithm of the second communication server described in the above embodiment is merely an example, and the image forming state adjustment system of the present invention is not limited to this.

  For example, the above-mentioned weight (imaging performance weight, weight of each evaluation point in the field of view), target (target value of imaging performance at each evaluation point in the field of view), optimization field range The designation or the like may not necessarily be possible. This is because these can be dealt with by specifying in advance by default settings as described above.

  For the same reason, it is not always necessary to specify an allowable value or a constraint condition.

  On the other hand, other functions not described above may be added. For example, the evaluation mode may be designated. Specifically, for example, an evaluation method such as an absolute value mode and a maximum / minimum width mode (for each axis, for the whole) can be designated. In this case, since the optimization calculation itself is always performed with the absolute value of the imaging performance as a target, the absolute value mode is set as a default setting and the maximum / minimum width mode is set as an optional mode.

  Specifically, the maximum / minimum width mode (range / offset for each axis) can be specified for those that can be subtracted as an offset for each X-axis and Y-axis axial direction, such as distortion. To do. In addition, the maximum and minimum width modes (range / overall offset) can be used for subtracting the average value of the entire XY plane, such as TFD (total astigmatism depending on in-plane uniformity of astigmatism and field curvature), as an offset. ) Can be specified.

  This maximum / minimum width mode is necessary when evaluating the calculation result. In other words, by determining whether or not the width is within the allowable value range, if the width is not within the allowable value range, it is possible to perform optimization calculation again by changing the calculation conditions (weight, etc.).

  In the above embodiment, the necessary ZS file is created by the above-described interpolation method. However, this is not necessarily required. For example, a ZS file may be created on the spot other than the interpolation method, or more types of ZS files are prepared in advance, and the ZS file with the closest condition is selected from the ZS files. It may be used.

  Further, in the above embodiment, the wavefront aberration calculated in the reference ID is used in the mode 1, the wavefront aberration actually measured in the mode 2 is used, and the wavefront aberration data similar to that in the mode 1 is obtained in the mode 3. For example, the wavefront aberration actually measured in the case of mode 3 may be used. That is, based on the actually measured wavefront aberration, the above-mentioned 12 types of aberrations under various exposure conditions may be obtained by calculation. If the above-mentioned best exposure conditions are determined based on the calculation results, Based on the above, it is possible to determine a more accurate best exposure condition.

  Further, in the case of mode 1 and mode 3, instead of using the calculated wavefront aberration in the reference ID, the actually measured wavefront aberration may be used. In short, wavefront aberration data may be used for the above-described optimization calculation.

  In addition, as described above, actual measurement data of individual imaging performance can be used instead of wavefront aberration. As described above, for example, a pattern image of a reticle is measured on the Z tilt stage 58 to measure the imaging performance. It is detected by an aerial image measuring instrument provided with a light receiving surface, or a reticle pattern is transferred onto a wafer and its transfer image (latent image or resist image) is detected, and the imaging performance is obtained from the detection result. But it ’s okay.

  In the above embodiment, the second communication server can set three modes from mode 1 to mode 3, but only mode 1, only mode 2, only mode 1 and mode 2, only mode 1 Only mode 3 and mode 2 and mode 3 may be settable.

  In the description so far, from the viewpoint of avoiding more complicated explanation than necessary, it is caused by fluctuations in the atmospheric pressure of the environment where the exposure apparatus is installed and the amount of energy of illumination light irradiated on the projection optical system. The point that the imaging performance of the projection optical system changes, that is, the so-called atmospheric pressure fluctuation and the so-called irradiation fluctuation of the imaging performance is not particularly mentioned. Also good.

  For example, atmospheric pressure fluctuation is monitored by monitoring the relationship between atmospheric pressure fluctuation and imaging performance (for example, wavefront aberration) in an environment where the projection optical system is actually installed, or by accommodating the projection optical system in a decompression chamber. Basic data can be obtained by changing the internal pressure in the decompression chamber and measuring the change in imaging performance at that time. Further, the irradiation fluctuation can be obtained as basic data by actually irradiating the projection optical system with illumination light and measuring the change in imaging performance at that time. Of course, it is also possible to obtain these basic data by high-precision optical simulation.

  On the other hand, in the above-described embodiment, when creating a database such as a wavefront aberration change table for the reference ID, the atmospheric pressure, the irradiation amount, etc. are assumed to serve as reference values, and these are taken into account by the above simulation. Create a database such as a wavefront aberration change table. For example, when the above-described mode 1 is selected, the second communication server 930 assumes that the calculated wavefront aberration in the reference ID is used, that is, when the image forming state is optimized, Measurement data of a sensor that measures the atmospheric pressure in the chamber 11 (or in the clean room) of the exposure apparatus 922 that is an adjustment amount calculation target, and irradiation in log data collected by the main controller 50 of the exposure apparatus 922 History data is taken in via the first communication server 920. Next, the second communication server 930 calculates the reference atmospheric pressure and the amount of variation from the irradiation amount based on these data, and the imaging performance of the projection optical system based on the calculation result. Atmospheric pressure fluctuation and irradiation fluctuation are calculated. Then, the second communication server 930 may perform the optimization process using the calculated wavefront aberration in the reference ID of mode 1 described above in consideration of the calculation result.

  For example, the optimization condition under the target exposure condition is not directly calculated based on the data such as the wavefront aberration change table under the reference ID (reference exposure condition), but between the reference ID and the target exposure condition. In addition, a third exposure condition in which at least one of the atmospheric pressure and the absorption amount of illumination light of the projection optical system is different from the reference ID is interposed, and data such as a wavefront aberration change table under the third exposure condition (described above) More accurate data such as wavefront aberration change table, etc. corrected by taking into account the atmospheric pressure fluctuation and irradiation fluctuation of the imaging performance of the projection optical system described above. Based on the obtained data, the optimization condition under the target exposure condition is calculated.

  In the case of mode 2 as well as mode 3, similarly, the atmospheric pressure fluctuation or irradiation fluctuation of the imaging performance of the projection optical system described above may be taken into consideration. This also applies to the modified examples described later.

  The above-described various changes in the processing algorithm of the second communication server can be easily realized by changing the software.

  The system configuration described in the above embodiment is merely an example, and the image forming state adjustment system according to the present invention is not limited to this. For example, as in the computer system shown in FIG. 22, a system configuration having a communication path that includes a public line 916 as a part thereof may be adopted.

  A computer system 10 ′ shown in FIG. 22 includes a lithography system 912 ′ in a semiconductor factory of a device manufacturer (hereinafter referred to as “manufacturer A” as appropriate) that is a user of a device manufacturing apparatus such as an exposure apparatus, and the lithography system. A computer system 914 of an exposure apparatus manufacturer (hereinafter referred to as “manufacturer B” as appropriate) connected to a part of 912 ′ via a communication path including a public line 916 is included.

The lithography system 912 'includes a first communication server 920 connected to each other via the LAN918, first to third exposure apparatus 922 _{1 to 922 3,} and the first is configured to include an authentication proxy server 924 Yes.

Assume that addresses AD1 to AD4 for identification are assigned to the first communication server 920 and the first to third exposure apparatuses 922 _{1 to} 922 ₃ , respectively.

  The first authentication proxy server 924 is provided between the LAN 918 and the public line 916, and functions as a kind of firewall here. That is, the first authentication proxy server 924 prevents communication data flowing on the LAN 918 from leaking to the outside, passes only information from the outside with addresses AD1 to AD4, and passes other information. This prevents the LAN 918 from being illegally entered from the outside.

  The computer system 914 includes a second authentication proxy server 928 and a second communication server 930 that are connected to each other via a LAN 929. Here, it is assumed that the address AD5 for identification is assigned to the second communication server 930.

  Like the first authentication proxy server 924, the second authentication proxy server 928 prevents communication data flowing on the LAN 929 from leaking to the outside and protects the LAN 929 from unauthorized entry from the outside. Has the role of a firewall.

In the system 10 ′ of FIG. 22, data transmission from the _first to third exposure apparatuses 922 _{1 to} 922 ₃ to the outside is performed via the first communication server 920 and the first authentication proxy server 924, and from the outside. transmission of data for the first to third exposure apparatus 922 _{1 to 922 3} are performed via directly or first authentication proxy server 924 and the first communication server 920, via the first authentication proxy server 924 It is like that.

  The system 10 ′ in FIG. 22 uses the above-described optimization program installed in the second communication server 930 by a service engineer traveling on the maker A side, for example, during periodic maintenance of the exposure apparatus. Therefore, it is suitable for adjusting the formation state of the pattern projection image on the object in the exposure apparatus.

  In addition, the following configuration is possible with the system configuration of FIG. That is, aberrations that are difficult to correct by the automatic adjustment of the adjusting device described above may be included. In such a case, the service engineer at the site (manufacturer A side) measures the wavefront aberration, and sends the data to the second communication server 930 via the first communication server 920 and the public line 916, whereby the manufacturer B The skilled engineer displays the wavefront measurement data stored in the hard disk of the second communication server 930 on the display, analyzes the display contents, grasps the problem, and aberrations that are difficult with automatic adjustment Can be input from the keyboard or the like of the second communication server 930 and displayed on the screen of the display device 44 of the exposure apparatus 922 by communication. . A service engineer or the like on the maker A side can adjust the projection optical system in a short time by finely adjusting the lens assembly based on the display content of the screen.

  In the above embodiment and the modified example of FIG. 22, the case where the above-described optimization program is stored in the second communication server 930 has been described. However, the present invention is not limited to this, and the CD- provided in the first communication server 920 is provided. In a storage device such as a hard disk in which the first communication server 920 includes the optimization program and the database attached thereto, which are loaded with the optimization program and the database attached thereto in the ROM drive. It may be installed and copied. In this way, the first communication server 920 can perform the aforementioned optimization processing and the like only by receiving information from the exposure apparatus 922.

Further, as described above, in the interior of the hard disk or the like provided in the first communication server 920, the first to third exposure apparatus 922 _{1 to 922 3} target information to be achieved by, for example, resolution (resolving power), practical minimum line width ( Device rule), wavelength of illumination light EL (center wavelength, wavelength width, etc.), information on pattern to be transferred, and other information related to the projection optical system that determines the performance of other exposure apparatuses 922 _{1 to} 922 ₃ , which are target values The possible information is stored. Further, in the hard disk or the like provided in the first communication server 920, target information in an exposure apparatus scheduled to be introduced in the future, for example, information on a pattern planned to be used is stored as target information.

  Accordingly, the default setting of the mode is set to mode 3, and the software is changed so that the first communication server 920 itself performs various condition settings performed by the operator in the processing of mode 3 described above using the above information. By doing so, it is possible to automatically set the best exposure conditions.

  Alternatively, a CD-ROM storing an optimization program and a database attached thereto is loaded into the drive device 46 provided in the exposure apparatus 922, and the optimization program and the database attached thereto are stored from the CD-ROM drive into a storage device such as a hard disk. It may be installed and copied in 42. In this way, it is possible to perform the above-described optimization processing and the like with the exposure apparatus 922 alone. Instead of inputting pattern information by an operator, pattern information is obtained from a host computer of a device manufacturing factory of manufacturer A, or a barcode or a two-dimensional code attached to a reticle on which a pattern to be transferred to a wafer is formed. The exposure apparatus may read pattern information to obtain pattern information, and automatic adjustment of the projection optical system PL by the exposure apparatus may be possible without intervention of an operator or service engineer. In this case, the main controller 50 constitutes a processing device that controls the adjusting device described above.

  That is, main controller 50 executes the above-described mode 1 processing (including determination), and the adjustment information of the adjustment device and the imaging performance of the projection optical system under the reference exposure condition (reference ID). The optimum adjustment amount of the adjustment device under the target exposure condition is calculated based on the information on, for example, wavefront aberration, and the adjustment device is controlled based on the calculated adjustment amount. As a result, for the same reason as described above, the formation state of the pattern projection image on the wafer under an arbitrary target exposure condition is optimized almost automatically.

  Also in this case, various information can be included as the information on the imaging performance. For example, the information relating to the imaging performance may include information on the wavefront aberration of the projection optical system after adjustment in the reference ID, or the single wavefront aberration of the projection optical system and the projection optical system under the reference ID Information on the imaging performance of the image may be included.

  Further, main controller 50 executes the above-described mode 2 processing, and the adjustment information of the adjustment device and the actual measurement data of the imaging performance (wavefront aberration or various aberrations) of the projection optical system under a predetermined target exposure condition. The optimal adjustment amount of the adjustment device under the target exposure condition is calculated based on the above, and the adjustment device is controlled based on the calculated adjustment amount. In this case, for the same reason as described above, the formation state of the pattern projection image on the wafer under an arbitrary target exposure condition is optimized almost automatically. In this case, the adjustment device is controlled based on a more accurate adjustment amount than in the first mode.

  In the above embodiment, when the wavefront aberration measurement data is used as the actual measurement data of the imaging performance of the projection optical system, for example, a wavefront aberration measuring instrument can be used to measure the wavefront aberration. Alternatively, a wavefront aberration measuring instrument having an overall shape replaceable with the wafer holder may be used. In such a case, this wavefront aberration measuring instrument uses a transfer system (such as a wafer loader) that loads a wafer or wafer holder onto wafer stage WST (Z tilt stage 58) and unloads it from wafer stage WST (Z tilt stage 58). Can be automatically conveyed. Note that the wavefront aberration measuring instrument carried into the wafer stage may not include all of the wavefront aberration measuring instrument 80 described above, for example, and only a part of the wavefront aberration measuring instrument 80 is provided outside the wafer stage. May be. Furthermore, in the above embodiment, the wavefront aberration measuring instrument 80 is detachable from the wafer stage, but may be permanently installed. At this time, only a part of the wavefront aberration measuring instrument 80 may be placed on the wafer stage, and the rest may be placed outside the wafer stage. Furthermore, in the above embodiment, the aberration of the light receiving optical system of the wavefront aberration measuring instrument 80 is ignored, but the wavefront aberration of the projection optical system may be determined in consideration of the wavefront aberration. Further, when the measurement reticle disclosed in, for example, the aforementioned US Pat. No. 5,978,085 is used for measuring the wavefront aberration, the latent image of the measurement pattern transferred and formed on the resist layer on the wafer is used. The positional deviation of the reference pattern with respect to the latent image may be detected by, for example, an alignment system ALG provided in the exposure apparatus. When detecting a latent image of a measurement pattern, a photoresist may be used as a photosensitive layer on an object such as a wafer, or a magneto-optical material may be used. In addition, the exposure device and coater / developer are connected in-line, and the resist image obtained by developing the wafer or other object to which the above-mentioned measurement pattern is transferred, and the etching image obtained by etching are exposed. You may detect with the alignment system ALG of an apparatus. In addition, a dedicated measuring device is provided separately from the exposure device to detect a transfer image (latent image, resist image, etc.) of the measurement pattern, and the result is transmitted to the exposure device via a LAN, the Internet, etc. or by wireless communication. You may send it. In addition to these, the mode setting of the above-mentioned optimization program is selected as the default setting. With such various ideas, it is possible to automatically perform the above-described automatic adjustment of the imaging performance of the projection optical system PL by the computer system 10 without intervention of an operator or a service engineer. Similarly, by storing the optimization program in the first communication server, the above-described automatic adjustment of the imaging performance of the projection optical system PL can be performed by the first communication server without intervention of an operator or service engineer. Can do. Similarly, by installing an optimization program in the storage device 42 of the exposure apparatus 922, the above-described automatic adjustment of the imaging performance of the projection optical system PL can be performed by the exposure apparatus alone without intervention of an operator or service engineer. It is also possible to do this.

  In addition, the first communication server 920 and the second communication server 930 may be connected by a wireless line.

  In the above-described embodiment and modification, twelve types of imaging performance are optimized. However, the type (number) of imaging performance is not limited to this, and the exposure condition to be optimized is not limited to this. By changing the type, more or less imaging performance may be optimized. For example, the imaging performance type included in the Zernike Sensitivity table as an evaluation amount may be changed.

In the embodiment and the modification, all the coefficients of the first to nth terms of the Zernike polynomial are used. However, the coefficients need not be used in at least one of the first to nth terms. good. For example, the corresponding imaging performance may be adjusted as usual without using the coefficients of the second to fourth terms. In this case, when the coefficients of the second to fourth terms are not used, the corresponding imaging performance is adjusted by adjusting the position of at least one of the movable lenses 13 _{1 to} 13 ₅ in the three-degree-of-freedom direction. However, it may be performed by adjusting the Z position and tilt of the wafer W (Z tilt stage 58).

  In the embodiment and the modification, the wavefront measuring apparatus calculates up to the 81st term of the Zernike polynomial, up to the 37th term in the case of the wavefront aberration measuring instrument, or calculates the 82nd term or more. However, the present invention is not limited to this. Similarly, the wavefront aberration change table described above is not limited to those relating to the first to 37th terms.

  Further, in the above embodiment and the modification, the optimization is performed by the least square method (Least Square Method) or the attenuated least square method (Damped Least Square Method) .For example, (1) Steepest Decent Method And gradient methods such as Conjugate Gradient Method, (2) Flecible Method, (3) Variable by Variable Method, (4) Orthonomalization Method, (5) Adaptive Method, (6) Quadratic Differential Method, (7 ) Grobal Optimization by Simulated Annealing, (8) Global Optimization by Biological evolution, (9) Genetic Algorithm (see US2001 / 0053962A), etc. can be used.

  In each of the above embodiments, a case where a LAN, or a LAN and a public line, and other signal lines are used as the communication path has been described. However, the present invention is not limited to this, and the signal line and the communication path may be wired or wireless.

  Further, in the above embodiment and the modification, as the information on the illumination conditions, the σ value (coherence factor) is used for normal illumination, and the annular ratio is used for annular illumination, but in addition to the annular ratio for annular illumination, Alternatively, an inner diameter or an outer diameter may be used. In modified illumination such as quadrupole illumination (also referred to as SHRINC or multipolar illumination), the light quantity distribution of illumination light on the pupil plane of the illumination optical system is one of them. The light quantity is increased in a plurality of partial areas whose light intensity centroids are set at positions where the distance from the optical axis of the illumination optical system is substantially equal, so that a plurality of partial areas (light intensity centroids) on the pupil plane of the illumination optical system Position information (for example, the coordinate value in the coordinate system with the optical axis as the origin on the pupil plane of the illumination optical system), the distance between the plurality of partial areas (light intensity centroids) and the optical axis of the illumination optical system, and the partial area Size (equivalent to σ value) May be used.

  Furthermore, in the above embodiment and the modification, the imaging performance is adjusted by moving the optical element of the projection optical system PL, but the imaging performance adjustment mechanism is not limited to the driving mechanism of the optical element, In addition to or instead of the drive mechanism, for example, the pressure of the gas between the optical elements of the projection optical system PL is changed, the reticle R is moved or inclined in the optical axis direction of the projection optical system, or the reticle and the wafer A mechanism for changing the optical thickness of the plane parallel plate disposed between the two may be used. However, in this case, the number of degrees of freedom in the embodiment or the modification can be changed.

In the embodiment and the modification, a plurality of exposure apparatuses 922 are provided, and the second communication server 930 is commonly connected to the plurality of exposure apparatuses 922 _{1 to} 922 ₃ via a communication path. Although described, the present invention is not limited to this, and it is needless to say that a single exposure apparatus may be used.

  In the above embodiment, the case where a stepper is used as the exposure apparatus has been described. However, the present invention is not limited to this. For example, the mask and the object disclosed in US Pat. A scanning exposure apparatus that transfers a pattern onto an object may be used.

  Further, in the above-described embodiment and modification, a plurality of exposure apparatuses have the same configuration. However, exposure apparatuses having different wavelengths of the illumination light EL may be mixed, or exposure apparatuses having different configurations, for example, stationary An exposure type exposure apparatus (such as a stepper) and a scanning exposure type exposure apparatus (such as a scanner) may be mixed. A part of the plurality of exposure apparatuses may be an exposure apparatus that uses a charged particle beam such as an electron beam or an ion beam. Further, for example, an immersion type exposure apparatus disclosed in International Publication WO99 / 49504 or the like in which a liquid is filled between the projection optical system PL and the wafer may be used.

  The use of the exposure apparatus in this case is not limited to the exposure apparatus for semiconductor manufacturing, but for example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern to a square glass plate, a plasma display, an organic EL, etc. The present invention can be widely applied to an exposure apparatus for manufacturing a display device, an image sensor (CCD, etc.), a thin film magnetic head, a micromachine, a DNA chip, and the like. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern.

The light source of the exposure apparatus of the above embodiment is not limited to an ultraviolet pulse light source such as an F ₂ laser, ArF excimer laser, or KrF excimer laser, but a continuous light source such as g-line (wavelength 436 nm), i-line (wavelength 365 nm), etc. It is also possible to use an ultra-high pressure mercury lamp that emits a bright line. Further, X-rays, particularly EUV light, etc. may be used as the illumination light EL.

In addition, a single wavelength laser beam oscillated from a DFB semiconductor laser or fiber laser is amplified by a fiber amplifier doped with, for example, erbium (or both erbium and ytterbium), and a nonlinear optical crystal is obtained. It is also possible to use harmonics that have been converted into ultraviolet light. Further, the magnification of the projection optical system may be not only a reduction system but also an equal magnification or an enlargement system. The projection optical system is not limited to a refraction system, and may be a catadioptric system (catadioptric system) having a reflection optical element and a refraction optical element or a reflection system using only a reflection optical element. When a catadioptric system or a reflective system is used as the projection optical system PL, the imaging performance of the projection optical system is improved by changing the position of the reflective optical element (such as a concave mirror or a reflective mirror) as the movable optical element described above. adjust. Further, when Ar ₂ laser light, EUV light or the like is used as the illumination light EL, the projection optical system PL may be an all reflection system composed of only a reflective optical element. However, when using Ar ₂ laser light or EUV light, the reticle R is also of a reflective type.

  For semiconductor devices, the step of designing the function and performance of the device, the step of manufacturing a reticle based on this design step, the step of manufacturing a wafer from a silicon material, and the pattern of the reticle on the wafer by the exposure apparatus of the above-described embodiment And a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like. According to this device manufacturing method, since exposure is performed in the lithography process using the exposure apparatus of the above-described embodiment, the imaging performance is adjusted according to the target pattern, or the result is based on the measurement result of the wavefront aberration. Since the pattern of the reticle R is transferred onto the wafer W via the projection optical system PL whose image performance is adjusted with high accuracy, it becomes possible to transfer the fine pattern onto the wafer W with good overlay accuracy. Therefore, the yield of the device as the final product is improved, and the productivity can be improved.

  As described above, the image formation state adjustment system of the present invention is suitable for quickly optimizing the formation state of a pattern projection image on an object. The exposure method and the exposure apparatus of the present invention are suitable for accurately transferring onto a pattern object. The program and the information recording medium of the present invention are suitable for causing a computer constituting a part of a control system of an exposure apparatus to execute processing for optimizing the formation state of a pattern projection image on an object. Yes. In addition, the projection optical system manufacturing method of the present invention is suitable for manufacturing a projection optical system with good imaging characteristics. The exposure apparatus manufacturing method of the present invention is suitable for manufacturing an exposure apparatus that can accurately transfer a fine pattern onto an object.

Claims (102)

An image formation state adjustment system for optimizing the formation state of the projection image on an object used in an exposure apparatus that forms a projection image of a predetermined pattern on the object using a projection optical system,
An adjusting device for adjusting the formation state of the projected image on the object;
Information on the difference between the imaging performance of the projection optical system and a predetermined target value of the imaging performance under exposure conditions that are connected to the exposure apparatus via a communication path and serve as at least one reference, and target exposure conditions A Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficient of each term of the Zernike polynomial below, and a parameter group showing the relationship between the adjustment of the adjustment device and the change in wavefront aberration of the projection optical system And a computer that calculates an optimum adjustment amount of the adjustment device under the target exposure condition using a relational expression between the wavefront aberration change table and the adjustment amount of the adjustment device . The image formation state adjustment system according to claim 1 ,
The image forming state adjusting system, wherein the predetermined target value is a target value of imaging performance at at least one evaluation point of the projection optical system input from the outside. The image formation state adjustment system according to claim 2 ,
The image forming state adjustment system, wherein the target value of the imaging performance is a target value of the imaging performance at the selected representative point. The image formation state adjustment system according to claim 2 ,
The target value of the imaging performance is converted into the target value of the coefficient set to improve the bad component based on the decomposition coefficient after the image formation performance of the projection optical system is analyzed by the aberration decomposition method. An image forming state adjusting system, characterized in that the image forming state adjustment target value is obtained. In the image forming condition adjusting system according to any one of claims 1 to 4,
The image forming state adjusting system according to claim 1, wherein the relational expression is an expression including a weighting function for weighting an arbitrary term among the terms of the Zernike polynomial. The image forming state adjustment system according to claim 5 ,
The image forming state adjusting system, wherein the computer displays the image forming performance of the projection optical system under the exposure condition as a reference color-coded with an allowable value as a boundary, and displays the weight setting screen. The image forming state adjustment system according to claim 5 ,
The image forming state adjusting system according to claim 1, wherein the weight is set such that a weight exceeding a permissible value in the imaging performance of the projection optical system under the reference exposure condition is increased. In the image formation state adjustment system according to any one of claims 1 to 7 ,
The image forming state adjusting system, wherein the computer creates a Zernike sensitivity table under a target exposure condition by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. In the image formation state adjustment system according to any one of claims 1 to 8 ,
The image forming state adjustment system, wherein the at least one reference exposure condition is the target exposure condition. In the image formation state adjustment system according to any one of claims 1 to 9 ,
The image forming state adjustment system, wherein the computer calculates the optimum adjustment amount further considering a constraint condition determined by a limit of an adjustment amount by the adjustment device. In the image formation state adjustment system according to any one of claims 1 to 10 ,
An image forming state adjusting system characterized in that the computer can set at least a part of the field of view of the projection optical system as an optimized field range from the outside. In the image formation state adjustment system according to any one of claims 1 to 11 ,
The image forming state adjusting system, wherein the computer controls the adjusting device based on the calculated adjustment amount. An image formation state adjustment system for optimizing the formation state of the projection image on an object used in an exposure apparatus that forms a projection image of a predetermined pattern on the object using a projection optical system,
An adjusting device for adjusting the formation state of the projected image on the object;
The present projection optical system connected to the exposure apparatus via a communication path and obtained based on adjustment information of the adjustment apparatus and information on wavefront aberration of the projection optical system under at least one reference exposure condition and wavefront aberration information, based on the Zernike sensitivity table showing the relationship between the coefficients of the terms of imaging performance and Zernike polynomials of said projection optical system at any exposure conditions, the exposure conditions before quinine meaning A computer for calculating the imaging performance of the projection optical system. The image formation state adjustment system according to claim 13 .
2. The image forming state adjusting system according to claim 1, wherein the arbitrary exposure condition is a condition determined according to first information relating to a pattern to be projected by the projection optical system and second information relating to a projection condition of the pattern. The image formation state adjustment system according to claim 14 ,
The image forming state adjustment system, wherein the second information includes a numerical aperture of the projection optical system and an illumination condition of the pattern. In the image formation state adjustment system according to any one of claims 13 to 15 ,
The image forming state adjustment system, wherein the computer creates a Zernike sensitivity table under the arbitrary exposure conditions by interpolation calculation based on the Zernike sensitivity tables under a plurality of reference exposure conditions. In the image formation state adjustment system according to any one of claims 1 to 16 ,
The image forming state adjusting system, wherein the communication path is a local area network. In the image formation state adjustment system according to any one of claims 1 to 16 ,
The image forming state adjusting system, wherein the communication path includes a public line. The image formation state adjustment system according to any one of claims 1 to 16 ,
The image forming state adjusting system, wherein the communication path includes a wireless line. In the image formation state adjustment system according to any one of claims 1 to 19 ,
2. The image forming state adjusting system according to claim 1, wherein the computer is a control computer that controls each component of the exposure apparatus. An exposure method for transferring a predetermined pattern onto an object using a projection optical system,
Information on the difference between the imaging performance of the projection optical system under at least one reference exposure condition and a predetermined target value of the imaging performance, and the imaging performance and Zernike of the projection optical system under the target exposure condition Zernike sensitivity table showing the relationship between coefficients of each term of the polynomial, adjustment of the adjustment device for adjusting the formation state of the projection image of the pattern on the object by the projection optical system, and change in wavefront aberration of the projection optical system Calculating an optimum adjustment amount of the adjustment device under the target exposure condition using a relational expression between a wavefront aberration change table including a parameter group indicating a relationship between the adjustment amount and the adjustment amount of the adjustment device;
And a step of transferring the pattern onto the object using the projection optical system in a state where the adjustment device is adjusted based on the calculated adjustment amount under the target exposure condition. The exposure method according to claim 21 , wherein
The exposure method according to claim 1, wherein the reference exposure condition is the target exposure condition. The exposure method according to claim 21 or 22 ,
The exposure method is characterized in that the relational expression is an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial. An exposure method for transferring a pattern onto an object via a projection optical system,
Based on information on the wavefront aberration of the projection optical system and a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, attention is paid out of a plurality of setting information in the transfer The imaging performance of the projection optical system is calculated under a plurality of exposure conditions having different setting values with respect to the setting information to be set, and the setting value related to the focused setting information is optimal based on the imaging performance calculated for each exposure condition. An exposure method for determining an exposure condition to be The exposure method according to claim 24 , wherein
The plurality of setting information includes information relating to a pattern to be projected by the projection optical system, and an exposure method for determining an optimum setting value using the information relating to the pattern as the setting information to be focused on. The exposure method according to claim 24 , wherein
The plurality of setting information includes a plurality of information related to a projection condition of a pattern to be projected by the projection optical system, and an optimum setting value is determined using one of the plurality of information related to the projection condition as the focused setting information. Exposure method. The exposure method according to claim 26 , wherein
The plurality of information related to the projection condition includes an optical information of the projection optical system and an optical information of an illumination optical system that illuminates the pattern. The exposure method according to claim 27 , wherein
An exposure method in which the optical information of the illumination optical system includes a plurality of information related to illumination conditions of the pattern. In the exposure method according to any one of claims 24 to 28 ,
An exposure method for calculating the imaging performance using a Zernike sensitivity table that differs at least in part of the plurality of exposure conditions. The exposure method according to claim 29 , wherein
An exposure method in which at least one of the plurality of exposure conditions has a corresponding Zernike sensitivity table created by interpolation based on a Zernike sensitivity table corresponding to the other plurality of exposure conditions. In the exposure method according to any one of claims 24 to 28 ,
Based on the wavefront aberration change table showing the relationship between the adjustment of the pattern image formation state by the projection optical system on the object and the change of the wavefront aberration of the projection optical system, and the Zernike sensitivity table, An exposure method for determining an optimum adjustment amount of the adjustment device under an exposure condition in which a setting value relating to the setting information of interest is optimum. The exposure method according to claim 31 , wherein
Exposure in which at least one optical element of the projection optical system is adjusted according to the optimal adjustment amount when the pattern is transferred to the object under an exposure condition where the setting value related to the setting information of interest is optimal. Method. The exposure method according to claim 31 or 32 ,
An exposure method for calculating the optimum adjustment amount using a weighting function for weighting at least one term of the Zernike polynomial. The exposure method according to any one of claims 31 to 33 ,
An exposure method for calculating the imaging performance using a Zernike sensitivity table that differs at least in part of the plurality of exposure conditions. The exposure method according to claim 34 , wherein
An exposure method in which at least one of the plurality of exposure conditions has a corresponding Zernike sensitivity table created by interpolation based on a Zernike sensitivity table corresponding to the other plurality of exposure conditions. An exposure method for transferring a pattern onto an object via a projection optical system,
Information on the wavefront aberration of the projection optical system, a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, and a pattern image by the projection optical system on the object The adjustment device under the exposure conditions in which the imaging performance of the projection optical system is optimized based on the adjustment by the adjustment device of the formation state and the wavefront aberration change table showing the relationship between the change of the wavefront aberration of the projection optical system An exposure method for determining the optimum adjustment amount. The exposure method according to claim 36 , wherein
An exposure method in which at least one optical element of the projection optical system is adjusted according to the optimal adjustment amount when a pattern is transferred onto the object under an exposure condition that optimizes the imaging performance. The exposure method according to claim 36 or 37,
An exposure method for calculating the optimum adjustment amount using a weighting function for weighting at least one term of the Zernike polynomial. In the exposure method according to any one of claims 36 to 38 ,
An exposure method for determining an optimum adjustment amount of the adjusting device that optimizes the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to at least one of a plurality of setting information in the transfer. 40. The exposure method according to claim 39 .
An exposure method in which the optimum adjustment amount is determined by using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions. The exposure method according to claim 40 , wherein
An exposure method in which at least one of the plurality of exposure conditions has a corresponding Zernike sensitivity table created by interpolation based on a Zernike sensitivity table corresponding to the other plurality of exposure conditions. In the exposure method according to any one of claims 39 to 41 ,
The plurality of setting information includes information regarding a pattern to be projected by the projection optical system, and the image forming performance of the projection optical system is optimized under a plurality of exposure conditions with different patterns. An exposure method for determining an adjustment amount. In the exposure method according to any one of claims 39 to 41 ,
The plurality of setting information includes projection information related to a projection condition of a pattern to be projected by the projection optical system, and the imaging performance of the projection optical system is optimal under a plurality of exposure conditions having different setting values related to the projection information. An exposure method for determining an optimum adjustment amount of the adjustment device. 44. The exposure method according to claim 43 .
The information on the projection condition includes optical information of the projection optical system and optical information of an illumination optical system that illuminates the pattern, and each of the plurality of exposure conditions has different set values for at least one of the two optical information. An exposure method for determining an optimum adjustment amount of the adjustment device that optimizes the imaging performance of the projection optical system. The exposure method according to claim 44 , wherein
The optical information of the illumination optical system includes a plurality of pieces of illumination information related to the illumination conditions of the pattern, and the imaging performance of the projection optical system respectively under a plurality of exposure conditions having different setting values relating to at least one of the plurality of pieces of illumination information An exposure method for determining an optimal adjustment amount of the adjustment device that optimizes the above. An exposure apparatus that transfers a pattern onto an object via a projection optical system,
A setting device that sets an exposure condition whose setting value is variable by at least one of a plurality of setting information related to the projection condition of the pattern to be projected by the projection optical system;
Based on the information on the wavefront aberration of the projection optical system and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, the setting to be focused on among the plurality of setting information The imaging performance of the projection optical system is calculated under each of a plurality of exposure conditions having different setting values with respect to information, and the setting value for the focused setting information is optimized based on the imaging performance calculated for each exposure condition. An exposure apparatus comprising: an arithmetic device that determines exposure conditions. The exposure apparatus according to claim 46,
An exposure apparatus that calculates the imaging performance using a Zernike sensitivity table that differs at least in part of the plurality of exposure conditions. 48. The exposure apparatus according to claim 47 , wherein
An exposure apparatus in which at least one of the plurality of exposure conditions has a corresponding Zernike sensitivity table created by interpolation based on a Zernike sensitivity table corresponding to the other plurality of exposure conditions. In the exposure apparatus according to any one of claims 46 to 48 ,
An adjustment device that adjusts a formation state of a pattern image by the projection optical system on the object; and a wavefront aberration change table showing a relationship between adjustment by the adjustment device and a change in wavefront aberration of the projection optical system; An exposure apparatus that determines an optimal adjustment amount of the adjustment apparatus under an exposure condition in which a setting value related to the setting information of interest is optimal based on the Zernike sensitivity table. The exposure apparatus according to claim 49,
Exposure in which at least one optical element of the projection optical system is adjusted according to the optimal adjustment amount when the pattern is transferred to the object under an exposure condition where the setting value related to the setting information of interest is optimal. apparatus. The exposure apparatus according to claim 49 or 50,
An exposure apparatus that calculates the optimum adjustment amount using a weighting function that weights at least one term of the Zernike polynomial. An exposure apparatus that transfers a pattern onto an object via a projection optical system,
An adjustment device that adjusts a formation state of a pattern image by the projection optical system on the object;
Information on the wavefront aberration of the projection optical system, a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, adjustment by the adjusting device, and wavefront aberration of the projection optical system An arithmetic unit that determines an optimum adjustment amount of the adjustment device under an exposure condition in which an imaging performance of the projection optical system is optimum based on a wavefront aberration change table showing a relationship with a change in apparatus. 53. The exposure apparatus according to claim 52 , wherein
An exposure apparatus that calculates the optimum adjustment amount using a weighting function that weights at least one term of the Zernike polynomial. The exposure apparatus according to claim 52 or 53,
An exposure apparatus that determines an optimal adjustment amount of the adjustment apparatus that optimizes the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to at least one of a plurality of setting information in the transfer. The exposure apparatus according to claim 54 ,
An exposure apparatus that determines the optimum adjustment amount by using a Zernike sensitivity table that differs in at least a part of the plurality of exposure conditions. 56. The exposure apparatus according to claim 55 .
An exposure apparatus in which at least one of the plurality of exposure conditions has a corresponding Zernike sensitivity table created by interpolation based on a Zernike sensitivity table corresponding to the other plurality of exposure conditions. An exposure apparatus that transfers a pattern onto an object via a projection optical system,
A setting device that sets an exposure condition whose setting value is variable by at least one of a plurality of setting information related to the projection condition of the pattern to be projected by the projection optical system;
Based on the information on the wavefront aberration of the projection optical system and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, the setting to be focused on among the plurality of setting information In order to calculate the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to information, a different Zernike sensitivity table is used in at least a part of the plurality of exposure conditions, and the different Zernike sensitivity table An exposure apparatus comprising: an arithmetic unit that generates at least one by interpolation calculation based on a plurality of other Zernike sensitivity tables. An exposure method for transferring a pattern onto an object via a projection optical system,
A pattern to be projected by the projection optical system based on information on the wavefront aberration of the projection optical system and a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial In order to calculate the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to the setting information of interest among a plurality of setting information related to the projection conditions, the difference is caused at least in a part of the plurality of exposure conditions An exposure method that uses a Zernike sensitivity table and creates at least one of the different Zernike sensitivity tables by interpolation calculation based on a plurality of other Zernike sensitivity tables. A device manufacturing method including a lithography process,
59. A device manufacturing method using the exposure method according to any one of claims 21 to 45 and 58 in the lithography process. An exposure apparatus that illuminates a mask with an energy beam and transfers a pattern formed on the mask onto an object via a projection optical system,
An adjusting device for adjusting a formation state of the projected image of the pattern on the object;
Which is connected via a signal line to the adjusting device, and the information of the difference between the predetermined target value of the imaging performance and said imaging performance of the previous SL projection optical system that put the exposure conditions comprising at least one reference, The Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system under the target exposure condition and the coefficient of each term of the Zernike polynomial, and the relationship between the adjustment of the adjustment device and the change in wavefront aberration of the projection optical system. An optimum adjustment amount of the adjustment device under the target exposure condition is calculated using a relational expression between a wavefront aberration change table including a parameter group and an adjustment amount of the adjustment device, and based on the calculated adjustment amount And a processing device for controlling the adjusting device. The exposure apparatus according to claim 60 , wherein
An exposure apparatus wherein the reference exposure condition is the target exposure condition. In the exposure apparatus according to claim 60 or 61 ,
An exposure apparatus, further comprising a wavefront measuring device for measuring wavefront aberration of the projection optical system. The exposure apparatus according to claim 62 , wherein
An object stage for holding the object;
An exposure apparatus, further comprising: a conveyance system that carries the wavefront measuring instrument onto the object stage and carries it out of the object stage. In the exposure apparatus according to any one of claims 60 to 63 ,
The image forming state adjusting system, wherein the predetermined target value is a target value of imaging performance at at least one evaluation point of the projection optical system input from the outside. The exposure apparatus according to claim 64 , wherein
The exposure apparatus characterized in that the imaging performance target value is the imaging performance target value at the selected representative point. The exposure apparatus according to claim 64 , wherein
The target value of the imaging performance is converted into the target value of the coefficient set to improve the bad component based on the decomposition coefficient after the image formation performance of the projection optical system is analyzed by the aberration decomposition method. An exposure apparatus characterized in that the target value of the formed imaging performance is obtained. The exposure apparatus according to any one of claims 60 to 66,
The exposure apparatus is characterized in that the relational expression is an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial. The exposure apparatus according to claim 67 , wherein
The exposure apparatus is characterized in that the imaging performance of the projection optical system under the reference exposure condition is color-coded with an allowable value as a boundary and the weight setting screen is displayed. In the exposure apparatus according to any one of claims 60 to 68 ,
The processing apparatus creates an Zernike sensitivity table under target exposure conditions by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. An exposure apparatus that illuminates a mask with an energy beam and transfers a pattern formed on the mask onto an object via a projection optical system,
An adjusting device for adjusting the formation state of the projected image on the object;
The current projection optical system connected to the adjustment device via a communication path and obtained based on adjustment information of the adjustment device and information on wavefront aberration of the projection optical system under at least one reference exposure condition A Zernike sensitivity table showing the relationship between the wavefront aberration information, the imaging performance of the projection optical system under the arbitrary exposure conditions under the adjustment state of the adjustment device according to the adjustment information, and the coefficients of each term of the Zernike polynomial And a processing device that calculates the imaging performance of the projection optical system under the arbitrary exposure conditions. The exposure apparatus according to claim 70 , wherein
The exposure apparatus characterized in that the arbitrary exposure condition is a condition determined according to first information relating to a pattern to be projected by the projection optical system and second information relating to a projection condition of the pattern. The exposure apparatus according to claim 71 , wherein
The exposure apparatus, wherein the second information includes a numerical aperture of the projection optical system and an illumination condition of the pattern. In the exposure apparatus according to any one of claims 70 to 72 ,
The processing apparatus creates the Zernike sensitivity table under the arbitrary exposure conditions by interpolation calculation based on the Zernike sensitivity tables under a plurality of reference exposure conditions. A projection image of a predetermined pattern is formed on an object using a projection optical system, and a part of a control system of an exposure apparatus including an adjustment device that adjusts a formation state of the projection image on the object is configured. A program for causing a computer to execute predetermined processing,
Information on the adjustment amount of the adjusting device under at least one reference exposure condition and information on the difference between the imaging performance of the projection optical system and the predetermined target value of the imaging performance under the reference exposure condition In response to the input, the Zernike sensitivity table showing the relationship between the difference, the imaging performance of the projection optical system under the target exposure condition, and the coefficient of each term of the Zernike polynomial, the adjustment of the adjustment device, and the projection A procedure for calculating an optimal adjustment amount of the adjustment device under the target exposure condition using a wavefront aberration change table including a parameter group indicating a relationship with a change in wavefront aberration of the optical system and a relational expression between the adjustment amounts For causing the computer to execute the program. The program according to claim 74 ,
A program for causing the computer to further execute a procedure for displaying a setting screen for the target value at each evaluation point in the field of view of the projection optical system. The program according to claim 74 ,
A procedure for decomposing components of the imaging performance of the projection optical system by an aberration decomposition method and displaying a setting screen for the target value together with a decomposition coefficient after the decomposition;
A program for causing the computer to further execute a procedure for converting a target value of a coefficient set in response to display of the setting screen into a target value of the imaging performance. In the program according to any one of claims 74 to 76 ,
The program is characterized in that the relational expression is an expression including a weighting function for weighting an arbitrary term in each term of the Zernike polynomial. The program according to claim 77 ,
A program for causing the computer to further execute a procedure for displaying the weight setting screen while displaying the image forming performance of the projection optical system under the exposure condition as a reference color-coded with an allowable value as a boundary. . In the program according to any one of claims 74 to 78 ,
A program for causing the computer to further execute a procedure for creating a Zernike sensitivity table under the target exposure condition by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. The program according to any one of claims 74 to 79,
A program for causing the computer to further execute a procedure for correcting the calculated optimum adjustment amount in consideration of a constraint condition determined by a limit of an adjustment amount by the adjustment device. The program according to any one of claims 74 to 80 ,
The reference exposure condition is the target exposure condition. The program according to any one of claims 74 to 81 ,
A program for causing the computer to further execute a procedure for controlling the adjustment device based on the calculated adjustment amount. A projection image of a predetermined pattern is formed on an object using a projection optical system, and a part of a control system of an exposure apparatus including an adjustment device that adjusts a formation state of the projection image on the object is configured. A program for causing a computer to execute predetermined processing,
Information on current wavefront aberration of the projection optical system obtained based on adjustment information of the adjustment device and information on wavefront aberration of the projection optical system under at least one reference exposure condition, and the adjustment according to the adjustment information Based on the Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system under an arbitrary exposure condition under the adjustment state of the apparatus and the coefficient of each term of the Zernike polynomial, the projection under the arbitrary exposure condition a step of calculating the imaging performance of the optical system;
A program for causing the computer to execute a procedure for outputting the calculation result . 84. The program according to claim 83 , wherein
The arbitrary exposure condition is a condition determined according to first information related to a pattern to be projected by the projection optical system and second information related to a projection condition of the pattern. The program according to claim 84,
The second information includes a numerical aperture of the projection optical system and an illumination condition of the pattern. The program according to any one of claims 83 to 85 ,
A program for causing the computer to further execute a procedure for creating a Zernike sensitivity table under the arbitrary exposure condition by interpolation calculation based on a Zernike sensitivity table under a plurality of reference exposure conditions. A computer program that causes an exposure apparatus that transfers a pattern onto an object via a projection optical system to execute a predetermined process,
A plurality of setting information in the transfer in response to input of information on the wavefront aberration of the projection optical system and a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial. The imaging performance of the projection optical system is calculated under a plurality of exposure conditions having different setting values with respect to the setting information of interest, and the setting relating to the setting information of interest is calculated based on the imaging performance calculated for each of the exposure conditions. A program for causing the computer to execute a procedure for determining an exposure condition with an optimum value. A computer program for causing an exposure apparatus including an adjustment device for adjusting a formation state of a projection image of the pattern on the object to execute a predetermined process in order to transfer the pattern onto the object via a projection optical system. And
Information on the wavefront aberration of the projection optical system, a Zernike sensitivity table showing the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, adjustment by the adjusting device, and wavefront aberration of the projection optical system In response to an input of a wavefront aberration change table indicating a relationship with a change in the step of determining an optimal adjustment amount of the adjustment device under exposure conditions under which the imaging performance of the projection optical system is optimal, A program to be executed by a computer. A computer program that causes an exposure apparatus that transfers a pattern onto an object via a projection optical system to execute a predetermined process,
In response to input of information related to the wavefront aberration of the projection optical system and a Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, the projection target by the projection optical system In order to calculate the imaging performance of the projection optical system under a plurality of exposure conditions having different setting values with respect to setting information of interest among a plurality of setting information related to the projection conditions of the pattern to be, at least one of the plurality of exposure conditions A program for causing the computer to execute a procedure of using at least one of the different Zernike sensitivity tables and generating at least one of the different Zernike sensitivity tables by interpolation calculation based on a plurality of other Zernike sensitivity tables.   90. A computer-readable information recording medium on which the program according to any one of claims 74 to 89 is recorded. A method for producing a projection optical system for projecting a predetermined pattern onto an object,
Obtaining information on the surface shape of each of the plurality of optical elements;
It assembles the projection optical system of the plurality of optical elements in the lens barrel assembly in a predetermined positional relationship, and obtaining information about the spacing of the optical surfaces of the optical elements during assembly;
Measuring the wavefront aberration of the projection optical system after the assembly;
Based on the information on the surface shape of each optical element and the information on the distance between the optical surfaces of each optical element, the optical data in the manufacturing process of the actually assembled projection optical system by correcting the known basic optical data A process of reproducing;
An adjustment including a wavefront aberration change table in which the relationship between the unit driving amount of each optical element in a predetermined degree of freedom direction and the change amount of the coefficient of each term of the Zernike polynomial is calculated based on the design value of the projection optical system Modifying a basic database based on the optical basic data;
Using the corrected database and the measurement result of the measured wavefront aberration, information on the adjustment amount of each direction of the lens element is calculated, and the at least one optical element is calculated based on the calculation result. Adjusting the projection optical system so that the measured wavefront aberration is optimized by driving in the direction of at least one degree of freedom . An exposure apparatus manufacturing method for transferring a predetermined pattern onto an object via a projection optical system,
Producing the projection optical system;
Incorporating the manufactured projection optical system into an exposure apparatus body;
Measuring the wavefront aberration of the projection optical system incorporated in the exposure apparatus body;
A database including a wavefront aberration change table in which a relationship between a unit driving amount of each optical element in a predetermined degree of freedom direction and a change amount of a coefficient of each term of a Zernike polynomial is calculated based on a design value of the projection optical system And the measured wavefront aberration, information on the amount of adjustment in each direction of freedom of the optical element is calculated, and based on the calculation result, the at least one optical element is moved in the direction of at least one degree of freedom. A method of manufacturing the exposure apparatus. An imaging performance measurement method for a projection optical system that projects a pattern onto an object,
Based on the information on the wavefront aberration of the projection optical system and the Zernike sensitivity table indicating the relationship between the imaging performance of the projection optical system and the coefficients of each term of the Zernike polynomial, attention is paid out of a plurality of setting information in the projection In order to calculate the imaging performance of the projection optical system under a plurality of conditions with different setting values with respect to setting information to be used, a different Zernike sensitivity table is used under at least a part of the plurality of conditions, and the different Zernike sensitivity table An imaging performance measurement method for a projection optical system, wherein at least one is created by interpolation calculation based on a plurality of other Zernike sensitivity tables. The imaging performance measurement method for a projection optical system according to claim 93 ,
The method for measuring imaging performance of a projection optical system, wherein the plurality of setting information includes information related to a projection condition of a pattern to be projected by the projection optical system. The imaging performance measurement method for a projection optical system according to claim 94 ,
The information on the projection condition includes the optical information of the projection optical system and the optical information of the illumination optical system that illuminates the pattern. The imaging performance measurement method for a projection optical system according to any one of claims 93 to 95 ,
The method for measuring imaging performance of a projection optical system, wherein the plurality of setting information includes information related to a pattern to be projected by the projection optical system. In the exposure method according to any one of claims 24 to 45 , 58 ,
The information on the wavefront aberration is estimated from information on the imaging performance of the projection shadow optical system. In the exposure method according to any one of claims 24 to 45 , 58 ,
The exposure method according to claim 1, wherein the information on the wavefront aberration is obtained from position information of a pattern image in an image plane of the projection optical system. In the exposure apparatus according to any one of claims 46 to 57 ,
An exposure apparatus characterized in that the information on the wavefront aberration is estimated from information on the imaging performance of the projection optical system. In the exposure apparatus according to any one of claims 46 to 57 ,
The exposure apparatus according to claim 1, wherein the information relating to the wavefront aberration is obtained from position information of a pattern image in an image plane of the projection optical system. The program according to any one of claims 87 to 89 ,
The information on the wavefront aberration is estimated from information on the imaging performance of the projection optical system. The program according to any one of claims 87 to 89 ,
The information on the wavefront aberration is obtained from position information of a pattern image in an image plane of the projection optical system.

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